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.

Examples

Input

aabxyyzz


Output

2


Input

byebye


Output

1


Input

abcdefghijklmnopqrstuvwxyz


Output

26


Input

abcabcxabcx


Output

3
#include<cstdio>
#include<iostream>
#include<cstring>
#define chkmin(a,b) a=min(a,b);
using namespace std;
const int maxn=300010;
int n,f[70000000],h[maxn];
char s[maxn];
int main()
{
	scanf("%s",s+1);n=strlen(s+1);
	memset(f,0x3f,sizeof(f));f[0]=0;
	for(int i=1;i<=n;i++)
		h[i]=h[i-1]^(1<<(s[i]-'a')); 
	for(int i=1;i<=n;i++)
		for(int j=0;j<26;j++)
			chkmin(f[h[i]],f[h[i]^(1<<j)]+1);
	printf("%d",max(1,f[h[n]]));
}