import java.io.*;

public class Main {

	public static void main(String[] args) {
		// TODO ?????????????????????????????????????????????
		try{
			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
			String[] str = br.readLine().split(" ");
			long a = Long.parseLong(str[0]);
			long b = Long.parseLong(str[1]);
			
			long[] ab = new long[2];
			ab[0] = Math.min(a, b);
			ab[1] = Math.max(a, b);
			System.out.println(GCD(ab));
			
		}catch(IOException e){
			System.out.println("IOException");
		}
	}
	
	static long GCD(long[] ab){
		long k;
		while(true){
			k = ab[1]%ab[0];
			if (k==0){
				return ab[0];
			}
			ab[1] = ab[0];
			ab[0] = k;
		}
	}

}
/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