import java.util.*;

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

        int ret = 0;
        while (true) {
            if (n == 1) {
                ret += m-1;
                break;
            }
            
            if (m < 0) {
                ret = -1;
                break;
            }
            
            if (m == n) break;

            if (m > n) {
                m -= n;
                ret++;
            } else {
                int tmp = m;
                m = n;
                n = tmp;
                ret++;
            }
        }
        
        System.out.println(ret);
    }
    
    public static int gcd(int a, int b) {
        if (b == 0) return a;
        int tmp = a;
        a = b;
        b = tmp%b;
        return gcd(a, b);
    }
}