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 (GCC 5.4.1) (judge verdict: Runtime Error)

#include<stdio.h>
char s[100010];
int min=1e9;
void f(int t,int v){//printf("%d %d %d\n",t,v,min);
  int i,c=0,b[30]={};
  for(i=t;s[i];i++){
    b[s[i]-'a']++;
    if(b[s[i]-'a']%2)c++;
    else c--;
    if(c==1)f(i+1,v+1);
  }//printf("%d %d %d\n",t,v,min);
  if(c<2&&min>v)min=v;
  //printf("%d %d %d\n",t,v,min);
}
int main(){
  scanf("%s",s);
  f(0,1);
  printf("%d\n",min);
}