#include <iostream>
#include <numeric>

using lint = long long;

void solve() {
    lint r = 0, m = 1;
    // x % m = r

    for (int i = 0; i < 3; ++i) {
        lint nr, nm;
        std::cin >> nr >> nm;

        for (int j = 0; j < nm; ++j) {
            if (r % nm == nr) break;
            r += m;
        }
        if (r % nm != nr) {
            std::cout << "-1\n";
            return;
        }

        nm /= std::gcd(m, nm);
        m *= nm;
        r %= m;
    }

    std::cout << r << "\n";
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}