using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ForYukicoder
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] str = new string[2];
            int[] X = new int[3];
            int[] Y = new int[3];

            for (int i = 0; i < 3; i++)
            {
                str = Console.ReadLine().Split();
                X[i] = int.Parse(str[0]);
                Y[i] = int.Parse(str[1]);
            }
            //----------------

            for (int a = 0; a < 1000000; a++)
            {
                if (a % Y[0] == X[0] && a % Y[1] == X[1] && a % Y[2] == X[2])
                {
                    Console.WriteLine(a);
                    return;
                }
            }
            Console.WriteLine(-1);
        }
    }
}