#include <bits/stdc++.h>
using namespace std;
using ll = long long;


int main() {
    ll X[3], Y[3];
    for (ll i = 0; i < 3; i++) {
        cin >> X[i] >> Y[i];
    }
    ll ans = X[0];
    int cnt = 0;
    while (ans % Y[1] != X[1] && cnt <= 1e7)
        ans += Y[0], cnt++;
    while (ans % Y[2] != X[2] && cnt <= 1e7)
        ans += lcm(Y[0], Y[1]), cnt++;
    if (cnt >= 1e7)
        ans = -1;
    cout << ans << endl;
}