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

void exgcd(ll a , ll b , ll&x , ll&y){
    if(b == 0){x = 1 , y = 0 ; return ;}
    exgcd(b , a % b , y , x) ;
    y -= a / b * x ;
}

ll gcd(ll x , ll y){
    if(y == 0)   return x ;
    gcd(y , x % y) ;
}

int main(){
    ios::sync_with_stdio(0);
    ll a , b , x , y , t ;
    cin>>a>>b;
    exgcd(a , b , x , y) ;
    t = gcd(a , b) ;
    x = (b / t + x % (b / t)) % (b / t) ;
    cout<<x;
    return 0 ;
}