#include <bits/stdc++.h>

using namespace std;

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

#define ll long long

int A, N;

void Euclid(ll &x, ll &y, int a, int b)
{
    if(b == 0) {
        x = 1;
        y = 0;
    }
    else {
        Euclid(x, y, b, a % b);
        ll aux = x;
        x = y;
        y = aux - y * (a / b);
    }
}

int main()
{
    fin.tie(NULL);
    fin >> A >> N;

    ll inv = 0, ins;
    Euclid(inv, ins, A, N);

    if(inv <= 0)
        inv = N + inv % N;

    fout << inv << "\n";
}