/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2021.05.17 18:40:07
**/

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

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