#include <bits/stdc++.h>

using namespace std;
int main() {
    int a, b, c, d, x, e, y;
    cin >> a >> b >> c >> d >> x >> e >> y;

    for (int i = 1; i <= 500; i++)
        for (int j = 1; j <= 500; j++)
            for (int k = 1; k <= 500; k++)
                if (i + j * b == a * k * b && i + j * d == c * k * d) {
                    for (int u = 1; u <= 500; u++)
                        if (u * x * k + (u - e) * y * k == (x + y) * j + i) {
                            cout << u << endl;
                            exit(0);
                        }
                }

    return 0;
}