#include<bits/stdc++.h>
// #include<atcoder/all>
// #include<boost/multiprecision/cpp_int.hpp>

using namespace std;
// using namespace atcoder;
// using bint = boost::multiprecision::cpp_int;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<ll,ll>;
using vi = vector<ll>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using ve = vector<vector<int>>;
using vb = vector<bool>;
using vvb = vector<vb>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
#define sz(c) ((ll)(c).size())
#define LB(A,x) (int)(lower_bound(A.begin(),A.end(),x)-A.begin())
#define UB(A,x) (int)(upper_bound(A.begin(),A.end(),x)-A.begin())
// #define MOD 1000000007
#define MOD 998244353
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<typename T>ostream&operator<<(ostream&os,vector<T>&v){for(int i = 0;i < v.size();i++)os<<v[i]<<(i+1!=v.size()?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>&p){os<<p.first<<" "<<p.second;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.first>>p.second;return is;}
template<typename T> inline bool chmax(T &a,T b){if(a < b){a = b;return true;}return false;}
template<typename T> inline bool chmin(T &a,T b){if(a > b){a = b;return true;}return false;}
ld dist(ld x1,ld y1,ld x2, ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}


long long extGcd(long long a, long long b, long long &p, long long &q) {  
    if (b == 0) { p = 1; q = 0; return a; }  
    long long d = extGcd(b, a%b, q, p);  
    q -= a/b * p;  
    return d;  
}
// 解が存在する時、リターン値を (x, M) とすると解は x ≡ r_i (mod M) for all i(M = lcm(m_i))
// 解なしの場合は (0, -1)
pair<long long, long long> crt(const vector<long long> &r, const vector<long long> &m) {
  long long x = 0, M = 1;
  for (int i = 0; i < (int)r.size(); ++i) {
	long long p, q;
	long long d = extGcd(M, m[i], p, q); // p is inv of M/d (mod. m[i]/d)
	if ((r[i] - x) % d != 0) return make_pair(0, -1);
	long long tmp = (r[i] - x) / d * p % (m[i]/d);
	x += M * tmp;
	M *= m[i]/d;
  }
  return make_pair((x + M)%M, M);
}


int main(){
  
  ios_base::sync_with_stdio(0), cin.tie(0);
  vi r(3),m(3);
  rep(i,3)cin >> r[i] >> m[i];
  rep(i,3)r[i] %= m[i];
  auto [x,M] = crt(r,m);
  if(M == -1)cout << "-1\n";
  else cout << x << "\n";
  

  return 0;
}