#include <fstream>
using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");

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

int main(){
  int a,b,x,y;
  f>>a>>b;
  int d = euclidExtins(a,b,x,y);
  while(x <= 0){
    x = (x + b) % b;
  }
  g<<x;

  return 0;
}