/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2021.05.17 18:32:11
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    int n;cin >> n;
    vector<int> a(n);
    int now = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        if (now == 0) now = a[i];
        else now = a[i]-1;
    }
    if (a[n-1]) puts("Alice");
    else puts("Bob");
    return 0;
}