#include <bits/stdc++.h>
using namespace std;
ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");
void euclid(long long a, long long b, long long &d, long long &x, long long &y)
{
    if(b == 0)
    {
        d = a;
        x = 1;
        y = 0;
    }
    else
    {
        long long x0, y0;
        euclid(b, a % b, d, x0, y0);
        x = y0;
        y = x0 - (a / b) * y0;
    }
}
int main()
{
    long long a, b, d, x, y;
    fin >> a >> b;
    euclid(a, b, d, x, y);
    if(x < 0)
        x += b;
    fout << x << "\n";
    return 0;
}