#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
#define pb push_back
#define mp make_pair
#define fi first
#define se second

int main()
{
	ll a[4];
	for(int i=0;i<4;i++)cin>>a[i];
	for(int i=0;i<3;i++)a[i]%=a[3];
	a[0]*=a[1];
	a[0]%=a[3];
	a[0]*=a[2];
	cout<<a[0]%a[3]<<endl;
	return 0;
}