#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <unordered_set>
#include <map>
#include <tuple>
#include <numeric>
#include <functional>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll, ll> P;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define exrep(i, a, b) for(ll i = a; i <= b; i++)
#define out(x) cout << x << endl
#define exout(x) printf("%.10f\n", x)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define pb push_back
#define re0 return 0
const ll mod = 1000000007;
const ll INF = 1e16;

// 戻り値 : gcd(a,b)
// ax + by = gcd(a,b) を満たす(x,y)が求まる
ll exGCD(ll a, ll b, ll &x, ll &y) {
    if(b == 0) {
        x = 1, y = 0;
        return a;
    }
    ll d = exGCD(b, a%b, y, x);
    y -= a/b * x;
    return d;
}

// x ≡ b_i (mod.m_i) の解xを求める
// 戻り値を (r,m) とすると解は x ≡ r (mod.m) (解なしの場合は(0,-1)) 
pair<ll, ll> CRT(const vl &b, const vl &m) {
    ll r = 0, M = 1;
    rep(i, (ll)b.size()) {
        ll p, q;
        ll d = exGCD(M, m[i], p, q);
        if((b[i] - r)%d != 0) {
            return make_pair(0, -1);
        }
        ll tmp = (b[i] - r)/d*p%(m[i]/d);
        r += M*tmp;
        M *= m[i]/d;
    }
    r = (r%M + M)%M;
    return make_pair(r, M);
}

int main() {

    vl x(3), y(3);
    rep(i, 3) {
        cin >> x[i] >> y[i];
    }

    P ans = CRT(x, y);

    if(x[0] + x[1] + x[2] == 0 || ans.second == -1) {
        out(ans.second);
    }
    else {
        out(ans.first);
    }
    
    re0;
}