Problem : spoj.com/problems/

Code : ideone.com/AKT4eU

import numpy as np
from numpy import linalg as LA
from fractions import gcd
def expo(A , m):
	if m==1:
		return A
	#print A
	p = 1
	for x in np.nditer(A):
		p = gcd(p,x)
	A /= p
	#A /= gcd( gcd(A[1][0],A[1][1] ),gcd(A[0][0],A[0,1] ) )
	C = np.matrix( "0,0 ; 0,0")
	#print C
	if ~m&1:
		C =  expo(A,m/2)*expo(A,m/2)
		return C
	else:
		C = A*expo(A,m/2)
		return C
A = np.matrix( "1,1 ; 1,2")
B = np.matrix( " 1;1")
t= input()
while t:
	t-=1
	n,mod = map(int,raw_input().split())
	if n==1:
		print "1/1"
	else:
		print (expo(A,n-1)*B) % mod

Approach : using matrix
[ 1 1 ] * [ A[n-1] ] = [ A[n] ]
[1 2 ] * [ B[n-1] ] = [ B[n] ]

Div the matrix by Gcd ( a11, a12 , a21 ,a 22) along to avoid overflow

I think my logic is correct , any hints to what i have done wrong? , is the matrix correct? , Please help!