#include <iostream>
#include <vector>
using namespace std;
int dfs(int now, int t, vector<vector<vector<int>>>&dp, vector<int>&A, bool turn){
    if(dp[turn][t][now] != -1) return dp[turn][t][now];
    if(turn){
        bool f = false;
        for(int j = 0; j < t; j++){
            if(j == 0) f |= dfs(now - 1, A[now - 1], dp, A, !turn);
            else f |= dfs(now, j, dp, A, !turn);
        }
        return dp[turn][t][now] = f;
    }
    else{
        bool f = true;
        for(int j = 0; j < t; j++){
            if(j == 0) f &= dfs(now - 1, A[now - 1], dp, A, !turn);
            else f &= dfs(now, j, dp, A, !turn);
        }
        return dp[turn][t][now] = f;
    }
}
int main(){
    int N;
    cin >> N;
    vector<int> A(N);
    for(int i = 0; i < N; i++) {
        cin >> A[i];
        if(A[i] > 1) A[i] = 2;
    }
    vector<vector<vector<int>>> dp(2, vector<vector<int>>(3, vector<int>(N, -1)));
    dp[1][0][0] = false;
    dp[1][1][0] = true;
    dp[1][2][0] = true;
    dp[0][0][0] = true;
    dp[0][1][0] = false;
    dp[0][2][0] = false;
    bool res = dfs(N - 1, A[N - 1], dp, A, true);
    if(res) cout << "Alice" << endl;
    else cout << "Bob" << endl;
}