n2 = exch2_neighbourId(4,n1)

         n3 = exch2_neighbourId(2,n1)

       exch2_neighbourId(1,12)=1

       exch2_neighbourId(2,12)=11

       exch2_neighbourId(3,12)=3

       exch2_neighbourId(4,12)=10

       exch2_neighbourId(1,2)=5

       exch2_neighbourId(2,2)=6

       exch2_neighbourId(3,2)=1

       exch2_neighbourId(4,2)=4

       exch2_neighbourId(5,2)=10

       exch2_neighbourId(1,3)=4

       exch2_neighbourId(2,3)=11

       exch2_neighbourId(3,3)=12

       exch2_neighbourId(4,3)=7

       exch2_neighbourId(5,3)=1

       exch2_neighbourId(1,4)=5

       exch2_neighbourId(2,4)=3

       exch2_neighbourId(3,4)=7

       exch2_neighbourId(4,4)=2

       exch2_neighbourId(1,5)=6

       exch2_neighbourId(1,1)=2

       exch2_neighbourId(2,5)=4

       exch2_neighbourId(3,5)=7

       exch2_neighbourId(4,5)=2

       exch2_neighbourId(1,6)=9

       exch2_neighbourId(2,6)=10

       exch2_neighbourId(3,6)=5

       exch2_neighbourId(4,6)=8

       exch2_neighbourId(5,6)=2

       exch2_neighbourId(2,1)=12

       exch2_neighbourId(1,7)=8

       exch2_neighbourId(2,7)=3

       exch2_neighbourId(3,7)=4

       exch2_neighbourId(4,7)=11

       exch2_neighbourId(5,7)=5

       exch2_neighbourId(1,8)=9

       exch2_neighbourId(2,8)=7

       exch2_neighbourId(3,8)=11

       exch2_neighbourId(3,1)=3

       exch2_neighbourId(4,8)=6

       exch2_neighbourId(1,9)=10

       exch2_neighbourId(2,9)=8

       exch2_neighbourId(3,9)=11

       exch2_neighbourId(4,9)=6

       exch2_neighbourId(1,10)=1

       exch2_neighbourId(2,10)=2

       exch2_neighbourId(3,10)=9

       exch2_neighbourId(4,1)=10

       exch2_neighbourId(4,10)=12

       exch2_neighbourId(5,10)=6

       exch2_neighbourId(1,11)=12

       exch2_neighbourId(2,11)=7

       exch2_neighbourId(3,11)=8

       exch2_neighbourId(4,11)=3

       exch2_neighbourId(5,11)=9

       INTEGER exch2_neighbourId(MAX_NEIGHBOURS,NTILES)

     &        exch2_nNeighbours,exch2_neighbourId,

       exch2_neighbourId(2,127)=123

       exch2_neighbourId(3,127)=128

       exch2_neighbourId(2,11)=7

       exch2_neighbourId(1,128)=132

       exch2_neighbourId(2,128)=124

       exch2_neighbourId(3,128)=129

       exch2_neighbourId(4,128)=127

       exch2_neighbourId(1,129)=133

       exch2_neighbourId(2,129)=125

       exch2_neighbourId(3,129)=130

       exch2_neighbourId(4,129)=128

       exch2_neighbourId(3,11)=12

       exch2_neighbourId(1,130)=134

       exch2_neighbourId(2,130)=126

       exch2_neighbourId(3,130)=157

       exch2_neighbourId(4,130)=129

       exch2_neighbourId(1,131)=135

       exch2_neighbourId(2,131)=127

       exch2_neighbourId(3,131)=132

       exch2_neighbourId(4,11)=10

       exch2_neighbourId(4,131)=81

       exch2_neighbourId(1,132)=136

       exch2_neighbourId(2,132)=128

       exch2_neighbourId(3,132)=133

       exch2_neighbourId(4,132)=131

       exch2_neighbourId(1,133)=137

       exch2_neighbourId(2,133)=129

       exch2_neighbourId(3,133)=134

       exch2_neighbourId(4,133)=132

       exch2_neighbourId(1,134)=138

       exch2_neighbourId(2,134)=130

       exch2_neighbourId(3,134)=161

       exch2_neighbourId(4,134)=133

       exch2_neighbourId(1,135)=139

       exch2_neighbourId(2,135)=131

       exch2_neighbourId(3,135)=136

       exch2_neighbourId(4,135)=81

       exch2_neighbourId(1,12)=16

       exch2_neighbourId(1,136)=140

       exch2_neighbourId(2,136)=132

       exch2_neighbourId(3,136)=137

       exch2_neighbourId(4,136)=135

       exch2_neighbourId(1,137)=133

       exch2_neighbourId(2,137)=138

       exch2_neighbourId(3,137)=136

       exch2_neighbourId(2,12)=8

       exch2_neighbourId(1,138)=141

       exch2_neighbourId(2,138)=134

       exch2_neighbourId(3,138)=165

       exch2_neighbourId(4,138)=137

       exch2_neighbourId(1,139)=142

       exch2_neighbourId(2,139)=135

       exch2_neighbourId(3,139)=140

       exch2_neighbourId(4,139)=80

       exch2_neighbourId(3,12)=38

       exch2_neighbourId(1,140)=143

       exch2_neighbourId(2,140)=136

       exch2_neighbourId(3,140)=139

       exch2_neighbourId(1,141)=144

       exch2_neighbourId(2,141)=138

       exch2_neighbourId(3,141)=169

       exch2_neighbourId(1,142)=23

       exch2_neighbourId(4,12)=11

       exch2_neighbourId(2,142)=27

       exch2_neighbourId(3,142)=139

       exch2_neighbourId(4,142)=143

       exch2_neighbourId(5,142)=80

       exch2_neighbourId(1,143)=17

       exch2_neighbourId(2,143)=20

       exch2_neighbourId(3,143)=140

       exch2_neighbourId(4,143)=142

       exch2_neighbourId(1,144)=1

       exch2_neighbourId(2,144)=5

       exch2_neighbourId(3,144)=141

       exch2_neighbourId(4,144)=173

       exch2_neighbourId(1,145)=149

       exch2_neighbourId(2,145)=110

       exch2_neighbourId(3,145)=114

       exch2_neighbourId(4,145)=146

       exch2_neighbourId(5,145)=118

       exch2_neighbourId(1,146)=150

       exch2_neighbourId(1,13)=17

       exch2_neighbourId(2,146)=102

       exch2_neighbourId(3,146)=106

       exch2_neighbourId(4,146)=147

       exch2_neighbourId(5,146)=145

       exch2_neighbourId(1,147)=151

       exch2_neighbourId(2,147)=94

       exch2_neighbourId(3,147)=98

       exch2_neighbourId(4,147)=148

       exch2_neighbourId(2,13)=9

       exch2_neighbourId(5,147)=146

       exch2_neighbourId(1,148)=152

       exch2_neighbourId(2,148)=86

       exch2_neighbourId(3,148)=90

       exch2_neighbourId(4,148)=34

       exch2_neighbourId(5,148)=147

       exch2_neighbourId(1,149)=153

       exch2_neighbourId(2,149)=145

       exch2_neighbourId(3,13)=14

       exch2_neighbourId(3,149)=150

       exch2_neighbourId(4,149)=122

       exch2_neighbourId(1,150)=154

       exch2_neighbourId(2,150)=146

       exch2_neighbourId(3,150)=151

       exch2_neighbourId(4,150)=149

       exch2_neighbourId(1,151)=155

       exch2_neighbourId(2,151)=147

       exch2_neighbourId(3,151)=152

       exch2_neighbourId(4,151)=150

       exch2_neighbourId(1,152)=156

       exch2_neighbourId(2,152)=148

       exch2_neighbourId(3,152)=34

       exch2_neighbourId(4,152)=151

       exch2_neighbourId(1,153)=157

       exch2_neighbourId(2,153)=149

       exch2_neighbourId(3,153)=154

       exch2_neighbourId(4,153)=126

       exch2_neighbourId(1,14)=18

       exch2_neighbourId(1,154)=158

       exch2_neighbourId(2,154)=150

       exch2_neighbourId(3,154)=155

       exch2_neighbourId(4,154)=153

       exch2_neighbourId(1,155)=159

       exch2_neighbourId(2,155)=151

       exch2_neighbourId(3,155)=156

       exch2_neighbourId(2,14)=10

       exch2_neighbourId(4,155)=154

       exch2_neighbourId(1,156)=160

       exch2_neighbourId(2,156)=152

       exch2_neighbourId(3,156)=33

       exch2_neighbourId(4,156)=155

       exch2_neighbourId(1,157)=161

       exch2_neighbourId(2,157)=153

       exch2_neighbourId(3,14)=15

       exch2_neighbourId(3,157)=158

       exch2_neighbourId(4,157)=130

       exch2_neighbourId(1,158)=162

       exch2_neighbourId(2,158)=154

       exch2_neighbourId(3,158)=159

       exch2_neighbourId(4,158)=157

       exch2_neighbourId(1,159)=163

       exch2_neighbourId(2,159)=155

       exch2_neighbourId(4,14)=13

       exch2_neighbourId(3,159)=160

       exch2_neighbourId(4,159)=158

       exch2_neighbourId(1,160)=164

       exch2_neighbourId(2,160)=156

       exch2_neighbourId(3,160)=33

       exch2_neighbourId(4,160)=159

       exch2_neighbourId(1,161)=165

       exch2_neighbourId(2,161)=157

       exch2_neighbourId(3,161)=162

       exch2_neighbourId(4,161)=134

       exch2_neighbourId(1,162)=166

       exch2_neighbourId(2,162)=158

       exch2_neighbourId(3,162)=163

       exch2_neighbourId(4,162)=161

       exch2_neighbourId(1,163)=167

       exch2_neighbourId(2,163)=159

       exch2_neighbourId(3,163)=164

       exch2_neighbourId(4,163)=162

       exch2_neighbourId(1,15)=19

       exch2_neighbourId(1,164)=168

       exch2_neighbourId(2,164)=160

       exch2_neighbourId(3,164)=32

       exch2_neighbourId(4,164)=163

       exch2_neighbourId(1,165)=169

       exch2_neighbourId(2,165)=161

       exch2_neighbourId(3,165)=166

       exch2_neighbourId(2,15)=11

       exch2_neighbourId(4,165)=138

       exch2_neighbourId(1,166)=170

       exch2_neighbourId(2,166)=162

       exch2_neighbourId(3,166)=167

       exch2_neighbourId(4,166)=165

       exch2_neighbourId(1,167)=171

       exch2_neighbourId(2,167)=163

       exch2_neighbourId(3,15)=16

       exch2_neighbourId(3,167)=168

       exch2_neighbourId(4,167)=166

       exch2_neighbourId(1,168)=172

       exch2_neighbourId(2,168)=164

       exch2_neighbourId(3,168)=32

       exch2_neighbourId(4,168)=167

       exch2_neighbourId(1,169)=173

       exch2_neighbourId(2,169)=165

       exch2_neighbourId(4,15)=14

       exch2_neighbourId(3,169)=170

       exch2_neighbourId(4,169)=141

       exch2_neighbourId(1,170)=174

       exch2_neighbourId(2,170)=166

       exch2_neighbourId(3,170)=171

       exch2_neighbourId(4,170)=169

       exch2_neighbourId(1,171)=175

       exch2_neighbourId(2,171)=167

       exch2_neighbourId(3,171)=172

       exch2_neighbourId(4,171)=170

       exch2_neighbourId(1,172)=176

       exch2_neighbourId(2,172)=168

       exch2_neighbourId(3,172)=31

       exch2_neighbourId(4,172)=171

       exch2_neighbourId(1,173)=1

       exch2_neighbourId(2,173)=169

       exch2_neighbourId(3,173)=174

       exch2_neighbourId(4,173)=144

       exch2_neighbourId(1,16)=12

       exch2_neighbourId(1,174)=2

       exch2_neighbourId(2,174)=170

       exch2_neighbourId(3,174)=175

       exch2_neighbourId(4,174)=173

       exch2_neighbourId(1,175)=3

       exch2_neighbourId(2,175)=171

       exch2_neighbourId(3,175)=176

       exch2_neighbourId(2,16)=42

       exch2_neighbourId(4,175)=174

       exch2_neighbourId(1,176)=4

       exch2_neighbourId(2,176)=172

       exch2_neighbourId(3,176)=31

       exch2_neighbourId(4,176)=175

       exch2_neighbourId(3,16)=15

       exch2_neighbourId(1,17)=20

       exch2_neighbourId(2,17)=13

       exch2_neighbourId(3,17)=18

       exch2_neighbourId(4,17)=143

       exch2_neighbourId(1,18)=21

       exch2_neighbourId(2,18)=14

       exch2_neighbourId(3,18)=19

       exch2_neighbourId(4,18)=17

       exch2_neighbourId(1,19)=15

       exch2_neighbourId(2,19)=18

       exch2_neighbourId(1,20)=23

       exch2_neighbourId(2,20)=17

       exch2_neighbourId(3,20)=21

       exch2_neighbourId(4,20)=143

       exch2_neighbourId(1,21)=24

       exch2_neighbourId(2,21)=18

       exch2_neighbourId(3,21)=20

       exch2_neighbourId(1,22)=26

       exch2_neighbourId(2,22)=50

       exch2_neighbourId(1,23)=27

       exch2_neighbourId(2,23)=20

       exch2_neighbourId(3,23)=24

       exch2_neighbourId(4,23)=142

       exch2_neighbourId(1,24)=28

       exch2_neighbourId(2,24)=21

       exch2_neighbourId(3,24)=25

       exch2_neighbourId(4,24)=23

       exch2_neighbourId(1,25)=29

       exch2_neighbourId(2,25)=26

       exch2_neighbourId(3,25)=24

       exch2_neighbourId(1,1)=5

       exch2_neighbourId(1,26)=30

       exch2_neighbourId(2,26)=22

       exch2_neighbourId(3,26)=54

       exch2_neighbourId(4,26)=25

       exch2_neighbourId(1,27)=77