#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}


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

Int mod_inverse(Int a,Int mod){
  Int x,y;
  extgcd(a,mod,x,y);
  return (mod+x%mod)%mod;
}

pair<Int, Int> linear_congruence(const vector<Int> &A,
                                 const vector<Int> &B,
                                 const vector<Int> &M){
  Int x=0,m=1;
  for(Int i=0;i<(Int)A.size();i++){
    Int a=A[i]*m,b=B[i]-A[i]*x,d=__gcd(M[i],a);
    if(b%d!=0) return make_pair(0,-1);
    Int t=b/d*mod_inverse(a/d,M[i]/d)%(M[i]/d);
    x=x+m*t;
    m*=M[i]/d;
  }
  return make_pair((x%m+m)%m,m);
}

//INSERT ABOVE HERE
signed main(){
  vector<Int> A(3,1),B(3),M(3);
  for(Int i=0;i<3;i++) cin>>B[i]>>M[i];
  auto p=linear_congruence(A,B,M);
  if(p.second==-1) cout<<-1<<endl;
  else cout<<(p.first?p.first:p.second)<<endl;
  return 0;
}