Problem:
Score : 400 points

Problem Statement

Snuke has decided to play a game using cards.
He has a deck consisting of N cards. On the i-th card from the top, an integer A_i is written.

He will perform the operation described below zero or more times, so that the values written on the remaining cards will be pairwise distinct. Find the maximum possible number of remaining cards. Here, N is odd, which guarantees that at least one card can be kept.

Operation: Take out three arbitrary cards from the deck. Among those three cards, eat two: one with the largest value, and another with the smallest value. Then, return the remaining one card to the deck.

Constraints

3 ≦ N ≦ 10^{5}

N is odd.

1 ≦ A_i ≦ 10^{5}

A_i is an integer.

Input

The input is given from Standard Input in the following format:

N
A_1 A_2 A_3 ... A_{N}

Output

Print the answer.

Sample Input 1

5
1 2 1 3 7

Sample Output 1

3

One optimal solution is to perform the operation once, taking out two cards with 1 and one card with 2. One card with 1 and another with 2 will be eaten, and the remaining card with 1 will be returned to deck. Then, the values written on the remaining cards in the deck will be pairwise distinct: 1, 3 and 7.

Sample Input 2

15
1 3 5 2 1 3 2 8 8 6 2 6 11 1 1

Sample Output 2

7

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

class Program {
	static void Main(string[] args) {
		new Calc().calc();
	}
	public class Calc {
		public Calc() { }
		public void calc() {
			int N = ReadLine<int>();
			var A = ReadLine<int>(' ').OrderBy(_ => _).ToList();
			var B = A.Distinct().Count();
			if (B%2==0) {
				(B - 1).WriteLine();
			} else {
				B.WriteLine();
			}
			return;
		}
	}

	public static T ReadLine<T>() {
		return (T)Convert.ChangeType(Console.ReadLine(), typeof(T));
	}

	public static T[] ReadLine<T>(params char[] separators) {
		return Console.ReadLine()
			.Split(separators)
			.Select(_ => (T)Convert.ChangeType(_, typeof(T)))
			.ToArray();
	}

	public static List<T> ReadLines<T>(int readCount) {
		List<T> rt = new List<T>();
		for (int i = 0; i < readCount; i++) {
			rt.Add(ReadLine<T>());
		}
		return rt;
	}
}
public static class Utils {
	public static string Docking<T>(this IEnumerable<T> s, int sequenceRange, Func<T, string> filter = null) {
		string str = "";
		int c = 0;
		foreach (var item in s) {
			str += filter == null ? item.ToString() : filter(item);
			c++;
			if (c == sequenceRange) break;
		}
		return str;
	}

	public static string Docking<T>(this IEnumerable<T> s, Func<T, string> filter = null) {
		return s.Docking(s.Count(), filter);
	}

	public static string RangeDocking<T>(this IEnumerable<T> s, int start, int end, Func<T, string> filter = null) {
		string str = "";
		end = end < s.Count() ? end : s.Count();
		var items = s.ToArray();
		for (int i = start; i < end; i++) {
			str += filter == null ? items[i].ToString() : filter(items[i]);
		}
		return str;
	}
	public static int IntParse(this string n) {
		return int.Parse(n);
	}
	public static void WriteLine<T>(this IEnumerable<T> list) {
		foreach (var item in list) {
			item.WriteLine();
		}
	}
	public static void WriteLine(this object obj) {
		Console.WriteLine(obj);
	}
	public static void AddTo<T>(this T obj,List<T> list) {
		list.Add(obj);
	}
}