public class gcd
{
	public static int gcd2(int a, int b) {
		int c;
        while (b != 0) {
            c = b;
            b = a % b;
            a = c;
        }
		return a;
	}

	public static int gcdn(int [] a) {
		int r = a[0];
        for (int i = 1; i < a.length; i++)
            r = gcd2(r, a[i]);
		return r;
	}

	public static void main(String [] argv) {
        int [] n = new int [argv.length];
        for (int i = 0; i < argv.length; i++) {
            n[i] = Integer.parseInt(argv[i]);
        }
        System.out.println(gcdn(n));
	}
}