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
import sys
input = sys.stdin.readline

S = list(input().rstrip())
INF = 10**15

bit = 0
dic = {0 : 0}
for ind, s in enumerate(S):
    bit ^= 1<<(ord(s)-97)
    score = INF
    if bit in dic:
        score = dic[bit] + 1
    for i in range(26):
        nbit = bit^(1<<i)
        if nbit in dic and dic[nbit]+1 < score:
            score = dic[nbit]+1
    if bit in dic and ind != len(S)-1:
        dic[bit] = min(dic[bit], score)
    else:
        dic[bit] = score

print(dic[bit])