#include<iostream>
#include <math.h>
#include <string>
#include <iomanip>
using namespace std;

int main(){
	long n,d;
	long a,b,c;
	long answer = 0;
	cin >> n >> d;
	b = n;
	c = d;
	while (1){
		a = b%c;
		if (a == 0){
			break;
		}
		b = c;
		c = a;
	}
	answer = (n*d / c) / d - 1;
	cout << answer << endl;



	return 0;
}