#include <iostream>
#include <fstream>
#include <stack>
#include <algorithm>
#include <string>
#include <queue>
#include <vector>
#include <map>
#include <cmath>
#include <stdio.h>

using namespace std;

ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");



void gcd(int a, int b, long long& x, long long& y) {
 if (a == 0) {
  x = 0;
  y = 1;
  return;
 }

 long long x1, y1;

 gcd(b % a, a, x1, y1);

 x = y1 - (b / a) * x1;
 y = x1;
}

int main() {
 int A, N;

 fin >> A >> N;

 long long inv = 0, ins;

 gcd(A, N, inv, ins);

 if (inv < 0)
  inv = N + inv % N;

 fout << inv;

 return 0;
}