#include <iostream> 
#include <string>
using namespace std;
int main() {
    int a, b, c, d, e;
    cin >> a >> b >> c >> d >> e;
    int res;
    if (a == 0 && b == 0 && c == 0 && d == 0 && e == 0) {
        res= 0;
    } else {
        int abcd = (a == 0 ? 1 : a) * (b == 0 ? 1 : b) * (c == 0 ? 1 : c) * (d == 0 ? 1 : d);
        int sum = (a == 0 ? 0 : 1) * (b == 0 ? 1 : b) * (c == 0 ? 1 : c) * (d == 0 ? 1 : d) + (a == 0 ? 1 : a) * (b == 0 ? 0 : 1) * (c == 0 ? 1 : c) * (d == 0 ? 1 : d) + (a == 0 ? 1 : a) * (b == 0 ? 1 : b) * (c == 0 ? 0 : 1) * (d == 0 ? 1 : d) + (a == 0 ? 1 : a) * (b == 0 ? 1 : b) * (c == 0 ? 1 : c) * (d == 0 ? 0 : 1);
    	int all;
        res = (e!=0&&(e * abcd) % (abcd - sum) == 0&&(all = (e * abcd) / (abcd - sum))% (a == 0 ? 1 : a) == 0&& all % (b == 0 ? 1 : b) == 0 && all % (c == 0 ? 1 : c) == 0 && all % (d == 0 ? 1 : d) == 0)?all:-1;
    }
    cout<<res;
}