import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner koko = new Scanner(System.in);
        long[] x = new long[3];
        long[] y = new long[3];
        for(int i=0; i<3; i++){
            x[i]=koko.nextInt();
            y[i]=koko.nextInt();
        }
        long koubai = y[0]*y[1]/gcd(y[0],y[1]);
        long kouho = 0;
        long kuri = koubai/y[0];
        boolean ichi = false;
        for(long i=0; i<kuri+1; i++){
            long a = x[0]+i*y[0];
            if(a%y[1]==x[1]){
                kouho=a;
                ichi = true;
                break;
            }
        }
        if(!ichi){
            System.out.println(-1);
        }else{
            boolean flag = false;
            long koubaibai = koubai*y[2]/gcd(koubai,y[2]);
            long kurikuri = koubaibai/koubai;
            for(long i=0; i<kurikuri+1; i++){
                long b = kouho + i*koubai;
                if(b%y[2]==x[2]&&b>0){
                    System.out.println(b);
                    flag=true;
                    break;
                }
            }
            if(!flag){
            System.out.println(-1);
            }
        
        }
    }
    static long gcd(long a, long b){
        return a == 0 ? b : gcd(b%a, a);
    }
}