import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.math.BigDecimal;

public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    }
    
    int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    }
    
//    End Solution
}


  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}


  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }

  }

} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util import java.util.StringTokenizer; StringTokenizer java.util import java.math.BigDecimal; BigDecimal java.math public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    }
    
    int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    }
    
//    End Solution
}


  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}


  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }

  }

} Main static InputReader in; in static PrintWriter out; out public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
} main {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
} in = new InputReader(System.in) in new InputReader(System.in) out = new PrintWriter(System.out) out new PrintWriter(System.out) Solution solver = new Solution(); solver new Solution() solver.solve() solver.solve solver out.close() out.close out String[] args args static class Solution {
    void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    }
    
    int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    }
    
//    End Solution
} Solution void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    } solve {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    } int x = in.nextInt(); x in.nextInt() in.nextInt in int y = in.nextInt(); y in.nextInt() in.nextInt in int gcd = gcd(x ,y); gcd gcd(x ,y) gcd x y out.println(gcd) out.println out gcd int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    } gcd {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    } if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      } x < y x y {
        int tmp = x;
        x = y;
        y= tmp;
      } int tmp = x; tmp x x = y x y y= tmp y tmp while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      } y > 0 y 0 {
        int r = x % y;
        x = y;
        y = r;    
      } int r = x % y; r x % y x y x = y x y y = r y r return x; x int x x int y y static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }

  } InputReader public BufferedReader br; br public StringTokenizer st; st public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    } InputReader {
      br = new BufferedReader(new InputStreamReader(stream));
    } br = new BufferedReader(new InputStreamReader(stream)) br new BufferedReader(new InputStreamReader(stream)) InputStream stream stream public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    } nextInt {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return Integer.parseInt(st.nextToken()); Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    } nextLong {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return Long.parseLong(st.nextToken()); Long.parseLong(st.nextToken()) Long.parseLong Long st.nextToken() st.nextToken st public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    } next {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    } nextDouble {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return Double.parseDouble(st.nextToken()); Double.parseDouble(st.nextToken()) Double.parseDouble Double st.nextToken() st.nextToken st public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    }
    
    int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    }
    
//    End Solution
}


  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}


  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }

  }

} public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    }
    
    int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    }
    
//    End Solution
}


  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}


  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }

  }

} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.math.BigDecimal;

public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      int x = in.nextInt();
      int y = in.nextInt();
      
      int gcd = gcd(x ,y);
      out.println(gcd);
//      End solve()
    }
    
    int gcd(int x, int y) {
      if (x < y) {
        int tmp = x;
        x = y;
        y= tmp;
      }
      while (y > 0) {
        int r = x % y;
        x = y;
        y = r;    
      }
      
      return x;
    }
    
//    End Solution
}


  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}


  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }

  }

}