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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
char s[200005];
int n, tot, num[305], f[200005], sum[200005];
map < int, int > mp;
int main(){
	scanf( "%s", s + 2 );
	n = strlen( s + 2 );
	mp[0] = 1;
	for( int i = 2; i <= n + 1; i++ ){
		num[s[i]] ^= 1;
		if( num[s[i]] ) sum[i] = sum[i-1] + (1<<(s[i]-'a'));
		else sum[i] = sum[i-1] - (1<<(s[i]-'a'));
		
		f[i] = f[i-1] + 1;
		if( mp[sum[i]] ) f[i] = f[mp[sum[i]]];
		if( !mp[sum[i]] ) mp[sum[i]] = i;
	}
	if( sum[n + 1] == n ){
		puts("1");
		return 0;
	}
	printf( "%d\n", f[n + 1] );
	return 0;
}/*
bbbasbbdakhda
bbb a sbb d a k h d a
*/