#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>
#include <bitset>
#include <cassert>

using namespace std;

int main() {
    unsigned long A, B, C, D;
    cin >> A >> B >> C >> D;

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

}