#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <climits>

#define rep(i, m, n) for(int i=int(m);i<int(n);i++)
#define all(c) begin(c),end(c)

template<typename T1, typename T2>
inline void chmin(T1 &a, T2 b) { if (a > b) a = b; }

template<typename T1, typename T2>
inline void chmax(T1 &a, T2 b) { if (a < b) a = b; }

//改造
typedef long long int ll;
using namespace std;
#define INF (1 << 30) - 1
#define INFl (ll)5e15
#define DEBUG 0 //デバッグする時1にしてね
#define dump(x)  cerr << #x << " = " << (x) << endl
#define MOD 1000000007


//ここから編集する

ll gcd(ll a, ll b) {
    if (a < b) swap(a, b);
    if (a % b == 0) return b;
    return gcd(b, a % b);

}

ll extgcd(ll a, ll b, ll &x, ll &y) {
    ll d = a;
    if (b != 0) {
        d = extgcd(b, a % b, y, x);
        y -= (a / b) * x;
    } else {
        x = 1ll;
        y = 0ll;
    }

    return d;
}

ll mod_inverse(ll a, ll m) {
    ll x, y;
    extgcd(a, m, x, y);
    return (m + x % m) % m;
}

pair<ll, ll> chinese_youjo(const vector<ll> &B, const vector<ll> &M) {
    ll x = 0ll, m = 1ll;
    vector<ll> A(B.size(), 1ll);

    for (int i = 0; i < A.size(); ++i) {
        ll a = A[i] * m, b = B[i] - A[i] * x, d = gcd(M[i], a);
        if (b % d != 0) return make_pair(0, -1); //解がない
        ll t = b / d * mod_inverse(a / d, M[i] / d) % (M[i] / d);
        x = x + m * t;
        m *= M[i] / d;
    }

    return make_pair(x % m, m);
}

class Solve {
public:
    void input() {

    }

    void solve() {
        input();
        int n = 3;

        vector<ll> B, M;
        for (int i = 0; i < n; ++i) {
            ll b, m;
            cin >> b >> m;
            B.push_back(b);
            M.push_back(m);
        }

        auto tmp = chinese_youjo(B, M);
        if(tmp.second == -1){
            cout << -1 << endl;
            return;
        }
//        cout << tmp.first << " " << tmp.second << endl;
//        if(tmp.first < 0) tmp.first += tmp.second;
        tmp.first = (tmp.first + tmp.second) % tmp.second;

        cout << tmp.first << endl;


    }
};


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    Solve().solve();


    return 0;
}