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<cstring>
int oo,N,sum,g[67108864],f[200010],x[27],n;
char s[200010];
int min(int a,int b)
{
	if (a<b) return(a);
	return(b);
}
int main()
{
	oo=1000000000;
	scanf("%s",s);
	n=strlen(s);
	N=1<<26;
	for (int i=0;i<N;i++) g[i]=oo;
	g[0]=0;
	for (int i=0;i<26;i++) x[i]=1<<i;
	x[26]=0;
	sum=0;
	for (int i=0;i<n;i++)
	{
		sum=sum^(1<<(s[i]-'a'));
		f[i]=oo;
		for (int j=0;j<=26;j++) f[i]=min(f[i],g[x[j]^sum]+1);
		g[sum]=min(g[sum],f[i]);
	}
	printf("%d\n",f[n-1]);
	return 0;
}