#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
const int nmx=200005;
vector<int> a(nmx);
map<pair<int,bool>,bool> mp;
bool f(int k,bool al=true){
    if(mp.count({k,al})) return mp[{k,al}];
    if(k==0){
        return mp[{k,al}]=al;
    }
    if(a[k]>1){
        bool res;
        if(al) res=f(k-1,al)|f(k-1,!al);
        else res=f(k-1,al)&f(k-1,!al);
        return mp[{k,al}]=res;
    }
    else{
        return mp[{k,al}]=f(k-1,!al);
    }
}
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;cin >> n;
    a.resize(n);
    REP(i,n) cin >> a[i];
    cout << (f(n-1)?"Alice":"Bob") << endl;
}