#include <bits/stdc++.h>
using namespace std;

int main() {
	long long N; cin >> N;
	vector<long long> A(N);
	for (int i = 0; i < N; i++) cin >> A[i];
	bool flag = true;
	for (int i = N - 1; i >= 0; i--) {
		if (A[i] >= 2) break;
		if (flag) flag = false;
		else flag = true;
		if (i == 0) {
			if (flag) flag = false;
			else flag = true;
		}
	}

	if (flag) cout << "Alice" << endl;
	else cout << "Bob" << endl;
}