const INF: usize = 1usize << 60;

fn dfs(idx: usize, a: &Vec<usize>, dp: &mut Vec<Vec<usize>>) {
    if idx == 0 {
        return;
    }
    let cidx = if a[idx-1] == 1 { 0 } else { 1 };
    dfs(idx-1, a, dp);
    dp[idx][0] = 1 - dp[idx-1][1];
    if cidx == 0 {
        dp[idx][1] = dp[idx][0];
    } else {
        dp[idx][1] = 1;
    }
}

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let a: Vec<usize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let mut dp = vec![vec![INF; 2]; n+1];
    dp[0][0] = 0;
    dp[0][1] = 0;
    dfs(n, &a, &mut dp);
    if dp[n][if a[n-1] > 1 { 1 } else { 0 }] == 0 {
        println!("Bob");
    } else {
        println!("Alice");
    }
}