uva11730測資B

Input:
4 10
9 91
8 27
8 23
14 45
56 708
45 900
69 901
96 980
78 893
55 198
69 345
54 680
57 890
18 23
28 45
49 103
95 990
81 878
96 984
99 902
0 0
Output:
Case 1: 3
Case 2: 10
Case 3: 6
Case 4: -1
Case 5: 5
Case 6: 14
Case 7: 18
Case 8: 16
Case 9: 15
Case 10: 14
Case 11: 9
Case 12: 11
Case 13: 15
Case 14: 16
Case 15: -1
Case 16: 3
Case 17: -1
Case 18: 16
Case 19: 16
Case 20: 16
Case 21: 15