#include<bits/stdc++.h>
#define int long long

using namespace std;

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

int32_t main()
{
    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);
    
        int a, b, c, x, y, ans;
        cin >> a >> b;
        euclid(a, b, x, y);
        cout << (x + b) % b;
}