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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main()
{
	char s[101];
	scanf("%s", &s);
	
	int i, j, max[26] = {}, min = 101, tmp;
	for (i = 0; i < 26; i++) {
		tmp = 0;
		for (j = 0; s[j] != 0; j++) {
			if (s[j] != 'a' + i) tmp++;
			else {
				if (tmp > max[i]) max[i] = tmp;
				tmp = 0;
			}
		}
		if (tmp > max[i]) max[i] = tmp;
	}
	for (i = 0; i < 26; i++) if (max[i] < min) min = max[i];
	
	printf("%d\n", min);
	fflush(stdout);
	return 0;
}