uva : 374 - Big Mod

#include<stdio.h>
#include<string.h>
long bigmod(long b,long p,long m);
long square(long x);
int main()
{
     long b,p,m,i,j,k,l;
    while(scanf("%ld %ld %ld",&b,&p,&m)==3)
    {
        printf("%ld\n",bigmod(b,p,m));
    }
    return 0;
}

long bigmod(long b,long p,long m)
{
if (p == 0)
return 1;
else if (p%2 == 0)
return square(bigmod(b,p/2,m)) % m;
else
return ((b % m) * bigmod(b,p-1,m)) % m;
}

long square(long x)
{
    return (x*x);
}