Modular fibbonacci

#include<stdio.h>
#include<math.h>


long long Fib(long long n , long long m) 
{
long long i , k , h , t , j;
i = h = 1;
j = k = 0;

while (n > 0)
{
if (n%2 == 1)
{ // if n is odd
t = (j%m*h%m) % m;
j = ((i%m*h%m) % m + (j%m*k%m) % m + t % m) % m;
i = ((i%m*k%m)%m + t%m);
}
t = (h%m*h%m)%m;
h = ((2*k%m*h%m)%m + t%m)%m;
k = ((k%m*k%m)%m + t%m)%m;
n = (long long) n/2;
}
return j;
}


int main()
{
long long n , m , p  , res;
while(scanf("%lld%lld" , &n , &m) == 2)
{
p = (long long) pow(2 , m);


res = Fib(n , p);
printf("%lld\n" , res);
}
return 0;
}