#include <iostream>
using namespace std;
static inline unsigned long long qpow(unsigned long long base,unsigned long long pow_time,unsigned long long mod){
	unsigned long long ret = 1;
	while(pow_time){
		if(pow_time&1)	ret =(ret*base)%mod;
		pow_time>>=1;
		base*=base;
	}
	return ret;	
}
int main(){
    int a,b,p;
    cin >> a >> b >> p;
    cout << a << "^" << b << " mod " << p << "=" << qpow(a,b,p);
}

网上找的快速幂模板，改了一下