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;
typedef long long ll;
typedef pair<ll,ll> P;
int c[200000][26];
int dp[200000];
int t[26];

int check(){
  int cc=0;
  for(int i=0;i<26;i++)cc+=t[i]%2;
  return cc;    
}

int main(){
  string s;
  cin>>s;

  for(int i=0;i<s.size();i++){
    c[i][s[i]-'a']++;
    dp[i]=1e9;
  }

  for(int i=1;i<s.size();i++){
    for(int j=0;j<26;j++)
      c[i][j]+=c[i-1][j];
  }

  for(int i=0;i<s.size();i++){
    for(int j=0;j<26;j++)t[j]=c[i][j];
    if(check()<=1)dp[i]=1;
  }
  int k=1;
  for(int i=0;i<s.size();i++){
    if(dp[i]!=1e9)
      for(int j=k;j<s.size();j++){
	for(int k=0;k<26;k++)
	  t[k]=c[j][k]-c[i][k];
	if(check()<=1)dp[j]=min(dp[i]+1,dp[j]),k=j+1;
      }
  }

  cout<<dp[s.size()-1]<<endl;
  
  return 0;
}