using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class MainClass {
public static void Main() {
string[] presidents = {"Ad", "Ar", "Bu", "Bu", "Ca", "Cl"};
IEnumerable sequence = presidents.Where((p, i) => (i & 1) == 1);
foreach (string s in sequence)
Console.WriteLine("{0}", s);
}
}