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 / gcd(D, N) -1);
	}

	static long gcd(long a, long b) {
		int e = 0;
		while ((a & 1) == 0 && (b & 1) == 0) {
			a >>= 1;
			b >>= 1;
			e++;
		}
		a = reduce(a);
		b = reduce(b);

		while (b != 0 && b != 1) {
			long c = Math.abs(a - b);
			a = Math.min(a, b);
			b = c;
		}
		if (b == 0) {
			return (1 << e) * a;
		} else if (b == 1) {
			return 1 << e;
		} else {
			throw new AssertionError(b);
		}
	}

	static long reduce(long a) {
		while ((a & 1) == 0) {
			a >>= 1;
		}
		return a;
	}
}