import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.IOException;

public class Main {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    }

    static int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }


} import java.io.BufferedReader; BufferedReader java.io import java.io.BufferedWriter; BufferedWriter java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.OutputStreamWriter; OutputStreamWriter java.io import java.io.IOException; IOException java.io public class Main {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    }

    static int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }


} Main public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    } main {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); bw new BufferedWriter(new OutputStreamWriter(System.out)) String[] st = br.readLine().split(" "); st br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " int a = Integer.parseInt(st[0]); a Integer.parseInt(st[0]) Integer.parseInt Integer st[0] st 0 int b = Integer.parseInt(st[1]); b Integer.parseInt(st[1]) Integer.parseInt Integer st[1] st 1 bw.append(gcd(a, b) + "\n") bw.append bw gcd(a, b) + "\n" gcd(a, b) gcd a b "\n" bw.flush() bw.flush bw String args[] args static int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    } gcd {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    } if (b == 0) {
            return a;
        } b == 0 b 0 {
            return a;
        } return a; a return gcd(b, a % b); gcd(b, a % b) gcd b a % b a b int a a int b b public class Main {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    }

    static int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }


} public class Main {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    }

    static int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }


} Main
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.IOException;

public class Main {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String[] st = br.readLine().split(" ");
        int a = Integer.parseInt(st[0]);
        int b = Integer.parseInt(st[1]);
        bw.append(gcd(a, b) + "\n");
        bw.flush();
    }

    static int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }


}
