#include<fstream>

using namespace std;

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

int a,b,x,y;

void euclid(int a,int b,int &x,int &y)
{
    int x0,y0;

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

int main()
{
    in>>a>>b;
    euclid(a,b,x,y);
    while (x<0) x+=b;
    out<<x;
}