#include <bits/stdc++.h>
using namespace std;

// #include <atcoder/all>
// using namespace atcoder;
// using mint = modint1000000007;
// // using mint = modint998244353;

typedef int64_t Int;
#define all(x) (x).begin(), (x).end()
 
const double EPS = 1e-10;
const Int INF = 1e18;
const int inf = 1e9;
const Int mod = 1e9+7;
//const Int mod = 998244353;

template<class T> 
istream &operator>>(istream &is, vector<T> &v) { 
    for (auto &e : v) {
        is >> e; 
    }
    return is; 
}

bool print_space_enable = false;
void print() { 
    std::cout << '\n'; 
    print_space_enable = false;
}

template <class Head, class... Tail>
void print(Head&& head, Tail&&... tail) {
    if (print_space_enable) std::cout << " ";
    std::cout << fixed << setprecision(15) << head;
    print_space_enable = true;
    print(std::forward<Tail>(tail)...);
}

template<typename T>
void print(vector<T> v) {
    for (size_t i = 0; i < v.size(); i++) {
        if (i > 0) std::cout << " ";
        std::cout << v[i];
    }
    std::cout << '\n';
}

template<class T>
vector<T> make_vec(size_t n, T val) {
    return vector<T>(n, val);
}

template<class... Ts>
auto make_vec(size_t n, Ts... ts) {
    return vector<decltype(make_vec(ts...))>(n, make_vec(ts...));
}

bool is_overflow(Int a, Int b) {
    return a > INF / b;
}

Int f(Int a, Int m) {
    return (a % m + m) % m;
}

int64_t extgcd(int64_t a, int64_t b, int64_t &x, int64_t &y) {
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    }
    int64_t g = extgcd(b, a % b, y, x);
    y -= a / b * x;
    return g;
}

void solve() {
    Int b[3], m[3];
    for (Int i = 0; i < 3; i++) {
        cin >> b[i] >> m[i];
    }
    Int x = b[0], md = m[0];
    for (Int i = 1; i < 3; i++) {
        Int p, q;
        Int g = extgcd(md, m[i], p, q);
        if (x % g != b[i] % g) {
            print(-1);
            return;
        }
        Int sp = (b[i] - x) / g * p % (m[i] / g);
        x = f(sp * md + x, lcm(md, m[i]));
        md = md * (m[i] / g);
        //print(x % m[i]);
    }
    print(x == 0 ? md : x);
    // for (Int i = 0; i < 3; i++) {
    //     print(x % m[i]);
    // }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    //Int _t; cin >> _t; while (_t--) solve();
    return 0;
}