Case #1: 15
Case #2: 192
Case #3: 871
Case #4: 18
Case #5: IMPOSSIBLE
Case #6: 41
Case #7: 12
Case #8: IMPOSSIBLE
Case #9: 159
Case #10: 15
Case #11: IMPOSSIBLE
Case #12: 49
Case #13: 53
Case #14: IMPOSSIBLE
Case #15: 234
Case #16: IMPOSSIBLE
Case #17: 744
Case #18: 695
Case #19: 82
Case #20: 12