MyCRT

bool Crt (vector <ll>& Rems, vector <ll>& Mods, ll& x) {
    ll r1 = x = Rems[0], m1 = Mods[0], n = Rems.size();
    for (int i = 1; i < n; i++) {
        ll r2 = Rems[i], m2 = Mods[i];
        ll c = r2 - r1, g = gcd (m1, m2), p, q, l = lcm (m1, m2);
        if (Flex (r1, g) != Flex (r2, g))
            return false;
        g = DoExtendedGCD (m1, -m2, p, q);
        ll X = mul (Flex (p, l), Flex (c / g, l), l);
        X = Flex (X, l);
        x = r1 + mul (X, m1, l);
        x = Flex (x, l);
        r1 = x, m1 = l;
    }
    return true;
}