package yukicoder;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] X = new int[3];
		int[] Y = new int[3];

		for (int i = 0; i < 3; i++) {
			X[i] = sc.nextInt();
			Y[i] = sc.nextInt();
		}
		sc.close();

		for (long i = 1; i < 10000000; i++) {
			boolean check = true;
			for (int j = 0; j < 3; j++) {
				if (i % Y[j] != X[j]) {
					check = false;
					break;
				}
			}
			if (check) {
				System.out.println(i);
				return;
			}
		}
		System.out.println(-1);

	}

}