#include <bits/stdc++.h>

using namespace std;

int main()
{
    int k, m, n, d;
    cin >> k >> m >> n >> d;
    int i = 1;
    bool b = true;
    while(b){
        if(i % k == 0 && i % m == 0 && i % n == 0)
            if(i / k + i / m + i / n + d == i){
                cout << i;
                return 0;
            }
        ++i;
        if(i > 10000){
            cout << -1;
            return 0;
        }
    }

    return 0;
}

k, m, n, d = map(int, input().split())
i = 1
b = True
while b:
    if i % k == 0 and i % m == 0 and i % n == 0:
        if i / k + i / m + i / n + d == i:
            print(i)
            exit()
    i += 1
    if i > 10000:
        print(-1)
        exit()