Problem Link

After finding a lot of WA in this problem , I have found AC by seting the base value = 257 I tried randomly by setting differect prime value of the base but found WA until 257.There may be another solutions with another bases.

Now my query is how can i choose a proper base value in the contest time which will give AC..

My code :

Sorry for bad english and thanks in advance.

Problem link : (http://codeforces.net/problemset/problem/166/E)

How to solve this problem log(n) with binary exponentiation of some 2 × 2 matrix into power n. Needs some explanation in this problem .Thanks in advance.

Sorry for bad english.