import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO ?????????????????????????????????????????????
		Scanner sc = new Scanner(System.in);

		long a = sc.nextLong();
		long b = sc.nextLong();

		// a > b ??¨????????¢????????????
		if (a < b) {
			long temp = a;
			a = b;
			b = temp;
		}

		long d = 0; // d : gcd(a,b)
		while (true) {
			long r = a % b; // a == n*b + r ( r < b )

			if (r == 0) {
				d = b;
				break;
			}

			a = b;
			b = r;
		}

		System.out.println(d);
	}

}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz