import java.util.*;

public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	} main {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a = sc.nextInt(); a sc.nextInt() sc.nextInt sc int b = sc.nextInt(); b sc.nextInt() sc.nextInt sc while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		} a != b a b {
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		} if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			} a < b a b {
				b -= a;
			} b -= a b a if( a > b ){
				a -= b;
			} a > b a b {
				a -= b;
			} a -= b a b System.out.println(a) System.out.println System.out System System.out a String[] args args public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	}
} public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	}
} Main
import java.util.*;

public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		while( a != b ){
			if( a < b ){
				b -= a;
			} else if( a > b ){
				a -= b;
			}
		}
		
		System.out.println(a);
	}
}