Problem:
Score : 300 points

Problem Statement

Snuke can change a string t of length N into a string t' of length N - 1 under the following rule:

For each i (1 ≤ i ≤ N - 1), the i-th character of t' must be either the i-th or (i + 1)-th character of t.

There is a string s consisting of lowercase English letters.
Snuke's objective is to apply the above operation to s repeatedly so that all the characters in s are the same.
Find the minimum necessary number of operations.

Constraints

1 ≤ |s| ≤ 100

s consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

s

Output

Print the minimum necessary number of operations to achieve the objective.

Sample Input 1

serval

Sample Output 1

3

One solution is: serval → srvvl → svvv → vvv.

Sample Input 2

jackal

Sample Output 2

2

One solution is: jackal → aacaa → aaaa.

Sample Input 3

zzz

Sample Output 3

0

All the characters in s are the same from the beginning.

Sample Input 4

whbrjpjyhsrywlqjxdbrbaomnw

Sample Output 4

8

In 8 operations, he can change s to rrrrrrrrrrrrrrrrrr.

Solution in Python (3.8.2) (judge verdict: Wrong Answer)

from collections import Counter

S = input()

cnt = Counter(S).most_common()

#print(cnt)

cand = []
for t in cnt:
    k, v = t
    if v != cnt[0][1]:
        break
    cand.append(k)

anss = float('inf')
for c in cand:
    alp = c
    ans = 0
    tmp = 0
    for s in S:
        if s == alp:
            ans = max(ans, tmp)
            tmp = 0
        else:
            tmp += 1
    if tmp:
        ans = max(ans, tmp)
    anss = min(anss, ans)
print(anss)