#include <bits/stdc++.h>

using namespace std;

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

typedef long long unsigned llu;

void euclid(llu a,llu b,llu &x,llu &y)
{
    if(!b)
    {
        x=1;
        y=0;
    }else{
        llu aux;
        euclid(b,a%b,x,y);
        aux=x;
        x=y;
        y=aux-(a/b)*y;
    }
}

int main()
{
    llu a,n,x,y;
    fin>>a>>n;
    euclid(a,n,x,y);
    if(x<=0)x=n+x%n;
    fout<<x;
    return 0;
}