#include<fstream>
#include<vector>
using namespace std;

ifstream cin("inversmodular.in");
ofstream cout("inversmodular.out");
#define ll long long

ll a,n,x,y;

ll gcd(ll a, ll b, ll &x, ll &y){
  if (!b) return x=1,y=0,a;
  ll x1,y1;
  ll g=gcd(b,a%b,x1,y1);
  x=y1;
  y=x1-y1*(a/b);
  return g;
}

int main()
{
    cin>>a>>n;
    ll g=gcd(a,n,x,y);
    x=(x%n+n)%n;
    cout<<x;
    return 0;
}