$Code$
#include <bits/stdc++.h>
using namespace std;
int g(int a, int b, int &x, int &y)
{
if (!b)
{
x = 1, y = 0;
return a;
}
int d = g(b, a % b, y, x);
y -= a / b * x;
return d;
}
int main()
{
int a, b;
cin >> a >> b;
int x, y;
g(a, b, x, y);
printf("%d\n", (x % b + b) % b);
return 0;
}