import java.io.*;

class EuclidApp {

  static int[] sides;

  public static void main(String[] args) throws Exception {
    System.out.print("Enter two side lengths separated by a space: ");
    System.out.flush();

    sides = getIntArray();

    int answer = Euclid(sides[0], sides[1]);

    System.out.println(answer);
  }

  public static int Euclid(int length, int width){

    //First find the longer side
    if(length > width) {

      //If there's no remainder, the LCD is width
      if((length % width) == 0){
        return width;
      }
      else {
        //Get the remainder to the nearest integer
        int lengthRemainder = (length % width);

        return Euclid(width, lengthRemainder);
      }
    }
    else {
      if((width % length) == 0) {
        return length;
      }
      else {
        int widthRemainder = (width % length);
        return Euclid(length, widthRemainder);
      }
    }
  }

  public static int[] getIntArray() throws IOException{

    InputStreamReader isr = new InputStreamReader(System.in);
    BufferedReader br = new BufferedReader(isr);

    String input = br.readLine();

    //Split into String array by space
    String[] token = input.split(" ");

    //Create int array
    int[] ints = new int[token.length];

    //Store strings in int array
    for(int i=0; i<token.length; i++){
      ints[i] = Integer.parseInt(token[i]);
    }
      return ints;
  }
}