50 15
1877 2 0
1777 3 0
1677 4 0
1577 5 0
1477 6 0
1377 7 0
1277 8 0
1177 9 0
1077 10 0
977 11 0
877 12 0
777 13 0
677 14 0
577 15 0
477 0