Fibonacci Finding in NlogN

Fibo.py

def multiply(a,b):
    result = [[0,0],[0,0]]
    for i in range(2):
        for j in range(2):
            summ = 0
            for k in range(2):
                summ += a[i][k]*b[k][j]
            result[i][j] = summ%(1000000007)
    return result

def findingfibo(a,b,n):
    ans = [[a+b,b],[b,a]]
    matrix = [[1,1],[1,0]]
    while n>0:
        if (n&1):
            ans = multiply(ans,matrix)
        matrix = multiply(matrix,matrix)
        n /= 2
    return ans[0][1]

a,b,n = map(int,raw_input().split())
print findingfibo(a,b,n-1)