#include <fstream>

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

long long T, i, a, b, c, D, n;
void euclid( long long &x, long long &y, long long  a, long long b){
    if( b == 0){
        x = 1;
        y = 0;
    }
    else{

    euclid(x, y , b, a % b);
    long long aux = x;
    x = y;
    y = aux - (a / b) * y;
    }
}
int main()
{
    fin >> a >> n;
    long long x = 0, y;
    euclid(x,y, a, n);
    if(x <= 0)
        x = n + x % n;
    fout << x;
    return 0;
}