#include <bits/stdc++.h>

using namespace std;

int euc(int a, int b, int& x, int& y)
{
    if(b == 0)
    {
        x = 1;
        y = 0;
        return a;
    }
    int x0, y0;
    int d = euc(b, a % b, x0, y0);
    x = y0;
    y = x0 - (a / b) * y0;
    return d;
}

int main()
{
    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);
    int a, b, x, y;
    scanf("%d%d", &a, &b);
    euc(a, b, x, y);
    while(x < 0) x += b;
    printf("%d", x);
    return 0;
}