#define forn(i, n) for (int i = 0; i < (int)(n); i++)

int n;
cin >> n;

int prev[n], next[n];
forn(i, n) {
  prev[i] = (i + n - 1) % n;
  next[i] = (i + 1) % n;
}
void Delete( int i ) {
  prev[next[i]] = prev[i];
  next[prev[i]] = next[i];
}
void Add( int after, int x ) {
  prev[x] = after;
  next[x] = next[after]
  next[prev[x]] = x;
  prev[next[x]] = x;
}