using System; using System.Linq; using CompLib.Collections; using CompLib.Util; public class Program { public void Solve() { var sc = new Scanner(); int n = sc.NextInt(); int x = sc.NextInt(); int[] a = new int[n].Select(i => sc.NextInt()).ToArray(); var map = new HashMap(); long ans = 0; foreach (var i in a) { ans += map[i ^ x]; map[i]++; } Console.WriteLine(ans); } public static void Main(string[] args) => new Program().Solve(); } namespace CompLib.Collections { using System.Collections.Generic; public class HashMap : Dictionary { public new TValue this[TKey key] { get { TValue o; return TryGetValue(key, out o) ? o : default(TValue); } set { base[key] = value; } } } } namespace CompLib.Util { using System; using System.Linq; class Scanner { private string[] _line; private int _index; private const char Separator = ' '; public Scanner() { _line = new string[0]; _index = 0; } public string Next() { while (_index >= _line.Length) { _line = Console.ReadLine().Split(Separator); _index = 0; } return _line[_index++]; } public int NextInt() => int.Parse(Next()); public long NextLong() => long.Parse(Next()); public double NextDouble() => double.Parse(Next()); public decimal NextDecimal() => decimal.Parse(Next()); public char NextChar() => Next()[0]; public char[] NextCharArray() => Next().ToCharArray(); public string[] Array() { _line = Console.ReadLine().Split(Separator); _index = _line.Length; return _line; } public int[] IntArray() => Array().Select(int.Parse).ToArray(); public long[] LongArray() => Array().Select(long.Parse).ToArray(); public double[] DoubleArray() => Array().Select(double.Parse).ToArray(); public decimal[] DecimalArray() => Array().Select(decimal.Parse).ToArray(); } }