#include<bits/stdc++.h>
using namespace std;
using ll = long long;


ll gcd(ll a,ll b){
    if(b) return gcd(b,a%b);
    return a;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false); 

    ll n,d;
    cin>>n>>d;
    ll g = gcd(n,d);
    ll need = n / g;
    cout<<need-1<<endl;
}