import java.util.*;

public class Main {
    private static Scanner sc = new Scanner(System.in);
    public static void main(String[] args) throws Exception {
        long n = sc.nextLong();
        long d = sc.nextLong();
        long m = gcd(n,d);

        System.out.println(n/m-1);
    }
    
    public static long gcd(long a, long b) {
        long tmp;
        while (b!=0) {
            tmp = a%b;
            a = b;
            b = tmp;
        }
        return a;
    }
}