#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define rrep(i,n) for(int i=1;i<(n);++i)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin,(a).rend()
#define dunk(a) cout << (a) << endl
using namespace std;
typedef long long ll;
const int inf = 1001001001;
const int mod = 1000000007;

ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	vector<ll> x(3), y(3);
	rep(i, 3) cin >> x[i] >> y[i];
	ll ans;
	ll pin = y[1] + 1;
	bool elf = false;
	rep(i, pin) {
		ll res = x[0] + y[0] * i;
		if (res % y[1] == x[1]) {
			elf = true;
			ans = res;
			break;
		}
	}
	if (!elf) { puts("-1"); return 0; }
	elf = false;
	pin = y[2] + 1;
	rep(i, pin) {
		ll res = ans + lcm(y[0], y[1]) * i;
		if (res % y[2] == x[2]) {
			elf = true;
			ans = res;
			break;
		}
	}
	if (!elf) { puts("-1"); return 0; }
	dunk(ans != 0 ? ans : lcm(y[0], lcm(y[1], y[2])));
	return 0;
}