#include <iostream>
#include <fstream>

// A * X mod N = 1

std::ifstream  cin("inversmodular.in");
std::ofstream cout("inversmodular.out");

int A, N, nr, a, b, c;

int euclid(int a, int b, int &x, int &y)
{
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    
    }
    
    int x0, y0, d;
    d = euclid(b, a % b, x0, y0);
    x = y0;
    y = x0 - (a / b) * y0; 
    return d;
   
}

int main () {

  cin >> A >> N;
  c = 1;

  int x, y, d;

  d = euclid(A, N, x, y);  
  cout << (x % N + N ) % N;      

  return 0;

}