// #include "../../merge_src_docs/template/24_template.hpp"
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define rep2(i, l, r) for(ll i = l; i < r; i++)

using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;

#define all(A) A.begin(), A.end()
#define elif else if
using pii = pair<ll, ll>;

bool chmin(auto &a, auto b) { return a > b ? a = b, 1 : 0; }
bool chmax(auto &a, auto b) { return a < b ? a = b, 1 : 0; }

struct IOSetup {
  IOSetup() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} iosetup;

template<class T>
void print(vector<T> a) {
  for(auto x : a) cout << x << ' ';
  cout << endl;
}

void print(auto x) { cout << x << endl; }

template<class Head, class... Tail>
void print(Head &&head, Tail &&...tail) {
  cout << head << ' ';
  print(forward<Tail>(tail)...);
}

//#include "../../merge_src_docs/math/crt.hpp"
/*
- `extgcd(ll a, ll b, ll &x, ll &y)` : `ax + by = gcd(a, b)` を満たす `x, y` を格納する．
`|x| + |y|` は最小化されるらしい
- `pair<ll, ll> crt(vll &r, vll &m)` : `x = r[i] (mod m[i])` を解く．
解が存在しないなら `{-1, -1}`, 存在するなら `{x, lcm(m[1], m[2], ...)}` を返す．
*/

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

ll inv_mod(ll x, ll m) {
  ll y, z;
  extgcd(x, m, y, z);
  return (y % m + m) % m;
}

pair<ll, ll> crt(vll r, vll m) {
  int n = r.size();
  ll r0 = 0, m0 = 1;
  rep(i, n) {
    ll g, im, x;
    g = extgcd(m0, m[i], im, x);
    if((r[i] - r0) % g) return {-1, -1};
    ll tmp = (r[i] - r0) / g * im % (m[i] / g);
    r0 += m0 * tmp;
    m0 *= m[i] / g;
  }
  return {(r0 % m0 + m0) % m0, m0};
}

// https://yukicoder.me/problems/447
void solve1() {
  vector<ll> X(3), Y(3);
  rep(i, 3) {
    ll x, y; cin >> x >> y;
    X[i] = x, Y[i] = y;
  }
  
  auto [r, m] = crt(X, Y);
  cout << r << '\n';
  
  return;
}

int main() {
  solve1();
  
  return 0;
}