#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++){
    cin >> A[i];
  }
  bool ok = true;
  for (int i = 1; i < N; i++){
    if (ok){
      if (A[i] == 1){
        ok = false;
      }
    } else {
      ok = true;
    }
  }
  if (ok){
    cout << "Alice" << endl;
  } else {
    cout << "Bob" << endl;
  }
}