Could you please provide more tests.
I have WA#2 No idea why! although all the tests in the other discussions succeeded including the original test case

Answer for #2 is P. So have to be carefull not to print ( sol + 1 ) % P. You have to print
just sol + 1 because months are numbered from 1 to P.

Tests:
20 30 1000 ans: 177
41 56 23   ans:  12
10 5 1000  ans: 185