#include <fstream>

using namespace std;
ifstream cin("inversmodular.in");
ofstream cout("inversmodular.out");
void euclid(int a , int b ,int & x ,int & y)
{
    if(b == 0)
    {
        x = 1, y = 1;
    }
    else
    {
        int x1 , y1;
        euclid(b , a % b , x1 , y1);
        x = y1;
        y = x1 - a / b * y1;
    }
}
int main()
{
    int a, b, x, y;
    cin >> a >> b;
    euclid(a, b, x, y);
    while(x < 0)
        x += b;
    cout << x;

    return 0;
}