package No400番台;

import java.util.Scanner;

public class Q415 {
	public static void main(String[] args) {
		new Q415().solver();
	}

	void solver() {
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		long D = sc.nextLong();
		System.out.println(N / Math.abs(gcd(D, N)) - 1);
	}

	static long gcd(long t1, long t2) {
		if (Math.abs(t1) < Math.abs(t2)) {
			long d = t2;
			t2 = t1;
			t1 = d;
		}
		if (t2 == 0)
			return t1;

		return gcd(t2, remainder(t1, t2));
	}

	static long remainder(long a, long b) {

		long r = a % b;
		if (Math.abs(r) > Math.abs(b / 2)) {
			if (r > 0 && b > 0) {
				r -= b;
			} else if (r > 0 && b < 0) {
				r += b;
			} else if (r < 0 && b > 0) {
				r += b;
			} else if (r < 0 && b < 0) {
				r -= b;
			} else {
				throw new AssertionError(a + " " + b);
			}
		}
		return r;
	}
}