被Hack代码

//# pragma GCC optimize("Ofast,no-stack-protector")
//
//# pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

# include <bits/stdc++.h>

typedef long long ll;

using namespace std;

ll a, b, mod;

ll quick_pow (ll a, ll b) {

	if (b < 2) //故意把这里错掉
		return a;

	ll x = quick_pow (a, b >> 1);

	if (b & 1)
		return a * x % mod * x % mod;

	return x * x % mod;

}

int main () {

//	freopen ("FM.in", "r", stdin);
//
//	freopen ("FM.out", "w", stdout);

	ios::sync_with_stdio (0);

	cin.tie (0);

	cout.tie (0);

	cin >> a >> b >> mod;

	cout << a << '^' << b << " mod " << mod << '=' << quick_pow (a, b);

	return 0;

}