#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
#define MOD 1999999973
void euclid(int a, int b, int &d, int &x, int &y)
{
    if(b == 0)
    {
        x = 1;
        y = 0;
        d = a;
        return;
    }
    int x1, y1;
    euclid(b, a%b, d, x1, y1);
    x = y1;
    y = x1 - (a/b)*y1;
}
int main()
{
   int d,x,y;
long long a,b;
       fin>>a>>b;
       euclid(a,b,d,x,y);
       while(x<0)
          x=x+b;
       fout<<x;

    return 0;
}