#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;
//using mint = modint1000000007;
//using mint = modint998244353;

int dp[2][200005];

int main(){
  int N;
  cin >> N;
  vector<int> v(N);
  rep(i,N) cin >> v[i];

  dp[0][0] = 1;
  dp[1][0] = -1;
  
  REP(i,1,N){
    if(v[i] > 1){
      if(dp[0][i-1] > 0 || dp[1][i-1] > 0) dp[0][i] = 1;
      else dp[0][i] = -1;
      if(dp[0][i-1] < 0 || dp[1][i-1] < 0) dp[1][i] = -1;
      else dp[1][i] = 1;
    }else{
      if(dp[1][i-1] > 0) dp[0][i] = 1;
      else dp[0][i] = -1;
      if(dp[0][i-1] > 0) dp[1][i] = 1;
      else dp[1][i] = -1;
    }
  }

  if(dp[0][N-1] > 0) cout << "Alice" << endl;
  else cout << "Bob" << endl;
  
  return 0;
}