Student of Binh Long Specialized And Gifted High School

long long power(long long a, long long b, long long mod)
{
    if (!b) return 1LL;
    long long T = power(a, b / 2, mod) % mod;
    return ((((T * T) % mod) * ((b & 1) ? (a % mod) : 1LL)) % mod);
}