#include <iostream>

using namespace std;

void euclid(int a, int b, int &x, int &y) {
    if(!b) {
        x = 1, y = 0;
    }
    else {
        int x1, y1;
        euclid(b, a%b, x1, y1);
        x = y1;
        y = x1 - a / b * y1;
    }
}

int main()
{
    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);
    cin.tie(nullptr)->sync_with_stdio(0);

    int a, b, x, y;
    cin >> a >> b;
    euclid(a, b, x, y);
    while(x < 0)
        x += b;
    cout << x;
    return 0;
}