A - Shrinking /

### 問題文

すぬけ君は、次のルールに従い、長さ N の文字列 t を長さ N - 1 の文字列 t' へ変えることができます。

• i (1 ≤ i ≤ N - 1) について、t'i 文字目は ti, i + 1 文字目のどちらかである。

### 制約

• 1 ≤ |s| ≤ 100
• s は英小文字のみからなる。

### 入力

s


### 入力例 1

serval


### 出力例 1

3


### 入力例 2

jackal


### 出力例 2

2


### 入力例 3

zzz


### 出力例 3

0


### 入力例 4

whbrjpjyhsrywlqjxdbrbaomnw


### 出力例 4

8


8 回の操作によって、srrrrrrrrrrrrrrrrrr へ変えることができます。

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: servalsrvvlsvvvvvv.

### Sample Input 2

jackal


### Sample Output 2

2


One solution is: jackalaacaaaaaa.

### 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.