#include <bits/stdc++.h>
#include <cmath>

using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");
int64_t a,n,x,y;
int64_t cmmdc(int64_t a,int64_t b,int64_t &x,int64_t &y)
{
    if(b==0)
    {
        x=1;
        y=0;
        return a;
    }
    int64_t X,Y,D;
    cmmdc(b,a%b,X,Y);
    x=Y;
    y=X-a/b*Y;
    return D;
}
int main()
{
    f>>a>>n;
    cmmdc(a,n,x,y);
    x%=n;
    if(x<0)
        x+=n;
    g<<x<<'\n';
}