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

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

int main()
{
    int a,b,x,y;
    fin>>a>>b;
    int d=euclid(a,b,x,y);
    while(x<0)
        x+=b;
    fout<<x;
    return 0;
}