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

long long extgcd(long long a, long long b, long long &x,long long &y){
    if(b == 0){x = 1,y = 0; return a;}
    long long g = extgcd(b,a%b,y,x);
    y -= a/b*x; return g;
}
 
pair<long long,long long> CRT2(vector<long long> &A,vector<long long> &M){
    long long ret = 0,lcm = 1;
    for(int i=0; i<A.size(); i++){
        long long a = A.at(i),m2 = M.at(i);
        long long x,y;
        long long g = extgcd(lcm,m2,x,y);
        if((a-ret)%g != 0) return{-1,-1};
        long long r = (a-ret)/g*x %(m2/g);
        ret += lcm*r; lcm *= m2/g;
    }
    return {(ret%lcm+lcm)%lcm,lcm};
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    vector<long long> A(3),M(3);
    for(int i=0; i<3; i++) cin >> A.at(i) >> M.at(i);
    auto[ans,lcm] = CRT2(A,M);
    if(lcm == -1) cout << -1 << endl;
    else if(ans == 0) cout << lcm << endl;
    else cout << ans << endl;
}