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)

ans=114514;
char s[111];
main()
{
	gets(s);
	for(int i=0;i<strlen(s);i++)
	{
		int m=0,k=0;
		for(int j=0;j<=strlen(s);j++)
		{
			if(j==strlen(s)||s[i]==s[j])
			{
				if(m<k)m=k;
				k=0;
			}
			else
			{
				k++;
			}
		}
		if(ans>m)ans=m;
	}
	printf("%d\n",ans);
}