代码：

#include<bits/stdc++.h>
using namespace std;
long long a,b,p;
long long fastpow(long long a,long long b,long long p){//经典快速幂
    long long res = 1;
    while(b != 0){
        if(b % 2 == 1){
            res = res * a % p;
        }
        a = a * a % p,b /= 2;
    }
    return res;
}
int main(){
    cin >> a >> b >> p;//输入
    cout << a << '^' << b << " mod " << p << '=' << fastpow(a,b,p) << endl;//输出
    return 0;
}