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

namespace Lib{
  ll extGCD(ll a, ll b, ll &x, ll &y){
    if(b==0){
      x=1,y=0;
      return a;
    }
    ll d=extGCD(b,a%b,y,x);
    y=y-a/b*x;
    return d;
  }
}
namespace Lib{  
pair<ll,ll> crt(vector<ll> r,vector<ll>m){
  assert(r.size()==m.size());
  ll ret_r=r[0],ret_m=m[0];
  int n=r.size();
  for(int i=1;i<n;i++){
    ll x=0,y=0,d=extGCD(ret_m,m[i],x,y);
    if((ret_r-r[i])%d!=0){
      return make_pair(-1ll,-1ll);
    }
    ret_r+=x*(r[i]-ret_r)/d%(m[i]/d)*ret_m;
    ret_m*=m[i]/d;
    ret_r%=ret_m;
  }
  return make_pair(ret_r,ret_m);
}
} // namespace Lib


int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  vector r(3,0ll),m(3,0ll);
  for(int i=0;i<3;i++){
    cin>>r[i]>>m[i];
  }
  auto [ans,l]=Lib::crt(r,m);
  if(ans==0)ans=l;
  cout<<ans<<'\n';
}