#include <iostream>
#include <fstream>
using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");
int a,b,r1,r2;
void im (int n,int m,int &i,int &j)
{

    if (m==0)
    {
        i=1;
        j=1;
    }
    else
    {
        int i1,j1;
        im(m,n%m,i1,j1);
        i=j1;
        j=i1-n/m*j1;
    }
    //cout<<i<<' '<<j<<'\n';
}
int main()
{
    f>>a>>b;
    im(a,b,r1,r2);
    while (r1<0)
        r1+=b;
    g<<r1;
    return 0;
}