14 16
15 17
14 15
15 16
16 17
3 120
4 121
5 122
3 20
1 10
10 100
100 1000
1000 10000
10000 100000
100000 1000000
1000000 10000000
10000000 100000000
100000000 1000000000
1 1000000000
0 0