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

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETLINE( A ) string A; getline( cin , A ) 
#define GETLINE_SEPARATE( A , SEPARATOR ) string A; getline( cin , A , SEPARATOR ) 
#define FOR_LL( VAR , INITIAL , FINAL_PLUS_ONE ) for( ll VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) 
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ ) 
#define REPEAT( HOW_MANY_TIMES ) FOR_LL( VARIABLE_FOR_REPEAT , 0 , HOW_MANY_TIMES ) 
#define RETURN( ANSWER ) cout << ( ANSWER ) << endl; return 0 
#define DOUBLE( PRECISION , ANSWER ) cout << fixed << setprecision( PRECISION ) << ( ANSWER ) << endl; return 0 
#define MIN( A , B ) A < B ? A : B;
#define MAX( A , B ) A < B ? B : A;
template <typename T> inline T Distance( const T& a , const T& b ){ return a < b ? b - a : a - b; }

constexpr const ll D = 30;
constexpr const ll P = 998244353;

int main(){
  CIN( ll , N );
  ll A[100000];
  FOR_LL( i , 0 , N ){
    CIN( ll ,Ai );
    if( i % 2 == 1 ){
      A[i / 2] = Ai;
    }
  }
  N /= 2;
  sort( A , A + N );
  ll i_start = 0;
  while( A[i_start] == 0 && i_start < N ){
    i_start++;
  }
  ll count = 0;
  if( i_start < N ){
    ll Ai_prev = A[i_start];
    FOR_LL( i , i_start , N ){
      ll& Ai = A[i];
      if( Ai != Ai_prev ){
	if( ( i - i_start ) % 2 == 1 ){
	  count++;
	}
	i_start = i;
	Ai_prev = Ai;
      }
    }
  }
  if( ( N - i_start ) % 2 == 1 ){
    count++;
  }
  RETURN( count % 2 == 0 ? "Bob" : "Alice" );
}