<pair>, coutner, counter base3
<, a>, 4, 10
<a, >, 4, 10
<, b>, 5, 11
<b, >, 5, 11
<, c>, 6, 12
<c, >, 6, 12
<, aa>, 10, 100
<a, a>, 10, 100
<aa, >, 10, 100
<, ab>, 11, 101
<a, b>, 11, 101
<ab, >, 11, 101
<, ac>, 12, 102
<a, c>, 12, 102
<ac, >, 12, 102
<, ba>, 13, 110
<b, a>, 13, 110
<ba, >, 13, 110
<, bb>, 14, 111
<b, b>, 14, 111
<bb, >, 14, 111
<, bc>, 15, 112
<b, c>, 15, 112
<bc, >, 15, 112
<, ca>, 16, 120
<c, a>, 16, 120
<ca, >, 16, 120
<, cb>, 17, 121
<c, b>, 17, 121
<cb, >, 17, 121
<, cc>, 18, 122
<c, c>, 18, 122
<cc, >, 18, 122
<, aaa>, 28, 1000
<a, aa>, 28, 1000
<aa, a>, 28, 1000
<aaa, >, 28, 1000
<, aab>, 29, 1001
<a, ab>, 29, 1001
<aa, b>, 29, 1001
<aab, >, 29, 1001
<, aac>, 30, 1002
<a, ac>, 30, 1002
<aa, c>, 30, 1002
<aac, >, 30, 1002