请问我哪里错了，例子对了的

#include<cstdio>
#include<iostream>
using namespace std;
int main(){ 
	long long a,b,c,d;
	cin>>a>>b>>c;
	d=a;
	for(long long i=1;i<=b;i++){
		a = ((a%c)*(a%c))%c;
	}
	cout<<d<<"^"<<b<<" "<<"mod"<<" "<<c<<"="<<a;
	return 0;
}