#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;

ll gcd(ll a, ll b){
    return b == 0 ? a : gcd(b, a%b);
}

bool comp(pair<ll,ll> a, pair<ll,ll> b){
    if(a.second != b.second)    a.second > b.second;
    else                        a.first > b.first;
}

int main(){
    pair<ll, ll> p[3];
    for(int i = 0; i < 3; i++)  cin >> p[i].first >> p[i].second;
    sort(p, p+3, comp);
    bool valid = true;
    for(int i = 1; i < 3; i++){
        for(int j = 0; j < i; j++){
            if(p[i].second%p[j].second) continue;
            valid &= (p[i].first%p[j].second)==p[j].first;
        }
    }
    if(!valid){
        cout << -1 << endl;
        return 0;
    }
    ll ans = p[2].first;
    while(ans%p[1].second != p[1].first)    ans += p[2].second;
    ll g = p[1].second*p[2].second/gcd(p[1].second,p[2].second);
    while(ans%p[0].second != p[0].first)    ans += g;
    cout << ans << endl;
    return 0;
}