Problem:
Score : 700 points

Problem Statement

We have a string s consisting of lowercase English letters.
Snuke is partitioning s into some number of non-empty substrings.
Let the subtrings obtained be s_1, s_2, ..., s_N from left to right. (Here, s = s_1 + s_2 + ... + s_N holds.)
Snuke wants to satisfy the following condition:

For each i (1 \leq i \leq N), it is possible to permute the characters in s_i and obtain a palindrome.

Find the minimum possible value of N when the partition satisfies the condition.

Constraints

1 \leq |s| \leq 2 \times 10^5

s consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

s

Output

Print the minimum possible value of N when the partition satisfies the condition.

Sample Input 1

aabxyyzz

Sample Output 1

2

The solution is to partition s as aabxyyzz = aab + xyyzz.
Here, aab can be permuted to form a palindrome aba, and xyyzz can be permuted to form a palindrome zyxyz.

Sample Input 2

byebye

Sample Output 2

1

byebye can be permuted to form a palindrome byeeyb.

Sample Input 3

abcdefghijklmnopqrstuvwxyz

Sample Output 3

26

Sample Input 4

abcabcxabcx

Sample Output 4

3

The solution is to partition s as abcabcxabcx = a + b + cabcxabcx.

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace atcoder
{
	class Program
	{
		static int In => int.Parse(Console.ReadLine());
		static int[] Ins => Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
		static void Out(bool b) => Console.WriteLine(b ? "Yes" : "No");

		static void Main(string[] args)
		{
			var str = Console.ReadLine();
			Dictionary<char, int> count = new Dictionary<char, int>();
			for (int i = 0;i < str.Length;i++)
			{
				if (count.ContainsKey(str[i])) count[str[i]]++;
				else count.Add(str[i], 1);
			}
			int ans = 0;
			foreach(var a in count)
			{
				if (a.Value % 2 == 1) ans++;
			}
			if (ans == 0) ans++;
			Console.WriteLine(ans);
			//Console.ReadLine();
		}
	}
}