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: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <ctype.h>
#include <string.h>
#define ll long long

int main(void){
int H,W,h,w;
scanf("%d%d%d%d",&H,&W,&h,&w);
if(H<h+1||W<w+1||h==1||w==1){
 printf("No\n");
 return 0;
}else{
printf("Yes\n");
int i,j;
for(i=0;i<H;i++){
for(j=0;j<W;j++){
 if(i==(h-1)&&j!=0&&j!=W-1)
 printf("%d",(-1)*h*w/(w-1));
 else printf("1");
 if(j!=W-1)
 printf(" ");
 else printf("\n");
}
}
}

return 0;
}