#include <iostream>
#include <fstream>
using namespace std;
int a,b,k,l,d;
void cmmdc(int a,int b,int &d,int &k,int &l)
{
    if (b==0)
    {
        l=0;
        k=1;
        d=a;
        return;
    }
    int kp,lp;
    cmmdc(b,a%b, d, kp, lp);
    k=lp;
    l=kp-lp*(a/b);
}

int main()
{
    ifstream fin("inversmodular.in");
    fin>>a>>b;
    ofstream fout("inversmodular.out");
    cmmdc(a,b,d,k,l);
    if(k>=0)
        fout<<k;
    else
    {
        while(k<0)
            k+=b;
        fout<<k;
    }
    return 0;
}