// includes #include // macros #define ll long long int #define pb emplace_back #define mk make_pair #define pq priority_queue #define FOR(i, a, b) for(int i=(a);i<(b);++i) #define rep(i, n) FOR(i, 0, n) #define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--) #define irep(st, itr) for(auto itr = (st).begin(); itr != (st).end(); ++itr) #define vrep(v, i) for(int i = 0; i < (v).size(); i++) #define all(x) (x).begin(),(x).end() #define sz(x) ((int)(x).size()) #define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end()) #define FI first #define SE second #define dump(a, n) for(int i = 0; i < n; i++)cout << a[i] << "\n "[i + 1 != n]; #define dump2(a, n, m) for(int i = 0; i < n; i++)for(int j = 0; j < m; j++)cout << a[i][j] << "\n "[j + 1 != m]; using namespace std; // types typedef pair P; typedef pair Pl; typedef pair Pll; typedef pair Pd; // constants const int inf = 1e9; const ll linf = 1LL << 50; const double EPS = 1e-10; const int mod = 1e9 + 7; // solve template bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;} template bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;} template istream &operator>>(istream &is, vector &vec){for(auto &v: vec)is >> v; return is;} template ostream &operator<<(ostream &os, const vector& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;} template ostream &operator<<(ostream &os, const set& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const unordered_set& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const multiset& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const unordered_multiset& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;} template ostream &operator<<(ostream &os, const pair &p){os << p.first << " " << p.second; return os;} template ostream &operator<<(ostream &os, const map &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;} template ostream &operator<<(ostream &os, const unordered_map &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;} template T extgcd(T a, T b, T &x, T &y){ T d = a; if(b != 0){ d = extgcd(b, a % b, y, x); y -= (a / b) * x; }else{ x = 1, y = 0; } return d; } template pair chinese_reminder_theorem(vector b, vector m){ T r = 0, M = 1; for(int i = 0; i < b.size(); i++){ T x, y; T d = extgcd(M, m[i], x, y); if((b[i] - r) % d != 0)return make_pair(0, -1); T tmp = (b[i] - r) / d * x % (m[i] / d); r += M * tmp; M *= m[i] / d; } return make_pair(r % M, M); } int main(int argc, char const* argv[]) { ios_base::sync_with_stdio(false); cin.tie(0); vector x(3), y(3); rep(i, 3)cin >> x[i] >> y[i]; auto p = chinese_reminder_theorem(x, y); if(p.FI == 0 && p.SE == -1)cout << -1 << endl; else cout << (p.FI == 0 ? p.FI + p.SE: p.FI) << endl; return 0; }