#define _CRT_SECURE_NO_WARNINGS
#include<sstream>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<cmath>
#include<string>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<numeric>
#include<functional>
#include<algorithm>
#include<bitset>
#include<tuple>
#include<unordered_set>
#include<random>
using namespace std;
#define INF (1<<29)
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define uniq(v) v.erase(unique(all(v)),v.end())


int gcd(int a,int b){
	if(b==0)return a;
	return gcd(b,a%b);
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	int n,d;
	cin>>n>>d;
	if(n==d)cout<<0<<endl;
	else{
		long long x = (long long)n*d / gcd(n,d) / d;
		cout<<x-1<<endl;
	}
	

	return 0;
}