请大佬帮忙

#include <bits/stdc++.h>
using namespace std;
	
int main()
{
	int n, m, k, x;	
	cin >> n >> m >> k >> x;
	m %= n;
	while(k >= 1)
	{
		m *= 10;
		m = m * m % n;
		k--;
	}
	m += x;
	m %= n;
	cout << m << endl;
	return 0;
}