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 int ll;
typedef long double ld;
inline void debugMode() {
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif // ONLINE_JUDGE
}
inline void PrintYes() { cout << "YES\n"; }
inline void PrintNo() { cout << "NO\n"; }

const int NMax = 2e5 + 5;

int code[NMax];
int ans[NMax];
int sz[NMax];
bool good[NMax];

map < int, int > Map;

int main(){
    //debugMode();

    string s;
    cin >> s;

    int n = (int)s.size();
    int cod = 0;
    for(int i = 1; i <= n; ++i) {
        cod ^= (1 << (s[i - 1] - 'a'));
        code[i] = cod;

        int aux = cod;
        while(aux % 2 == 0 && aux != 0) {
            aux /= 2;
        }
        if(aux == 1) good[i] = true;
    }

    ans[0] = 1;
    for(int i = 1; i <= n; ++i) {
        if(code[i] == 0 || good[i]) {
            sz[i] = i;
            ans[i] = 1;
            continue;
        }
        if(Map[code[i]] == 0) {
            if(sz[i - 1] % 2 == 0) { 
                ans[i] = ans[i - 1];
                sz[i] = sz[i - 1] + 1;
            } else {
                ans[i] = ans[i - 1] + 1;
                sz[i] = 1;
            }

            Map[code[i]] = i;
        } else {
            if(sz[i - 1] % 2 == 0) { 
                ans[i] = ans[i - 1];
                sz[i] = sz[i - 1] + 1;
            } else {
                ans[i] = ans[i - 1] + 1;
                sz[i] = 1;
            }

            if(ans[i] > ans[Map[code[i]]]) {
                ans[i] = ans[Map[code[i]]];
                sz[i] = i - Map[code[i]];
            }
        }
    }

    cout << max(1, ans[n]);
    return 0;
}