#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
//#define int long long
typedef long long ll;
using namespace std;

ll A, B, C, D;

signed main()
{
	cin >> A >> B >> C >> D;

	cout << ((((A % D) * (B % D)) % D) * (C % D)) % D << endl; 
}