/*******************************************************************************
* Name: Robert Sedgewick
* NetId: rs
* Precept: P255
*
* Description: Takes two positive integers p and q from standard input; prints
* out their greatest common factor.
*
* Dependencies: StdIn.java, StdOut.java
*
*****************************************************************************/
public class Part2 {
// recursive method to find gcf of p and q
public static int gcf(int p, int q) {
// base case
if (p == q) return p;
// call gcd with smaller and abs(difference)
int smaller = Math.min(p, q);
int difference = Math.abs(p - q);
return gcf(smaller, difference);
}
public static void main(String[] args) {
// input x, y from standard input
int x = StdIn.readInt();
int y = StdIn.readInt();
// print their greatest common factor
int g = gcf(x, y);
StdOut.println(g);
}
}