#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>


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

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