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 9.2.1) (judge verdict: Runtime Error)

#include <stdio.h>
#include <string.h>
typedef long long ll;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define max(l,r) (l>r?l:r)
#define min(l,r) (l<r?l:r)
#define swap(l,r) {ll tp=l;l=r;r=tp;}
const ll MOD = 1000000007;

int main(){
    int n;// scanf("%d",&n);
    char s[105]; scanf("%s",s);
    n = strlen(s);

    int cnt[30] = {0}, ans = MOD;
    rep(i,26){
        rep(j,n){
            if(s[j] == ('a'+i)) cnt[j] = 0;
            else{
                if(j>0) cnt[j] = cnt[j-1]+1;
                else cnt[j]=1;
            }
        }
        int mx = 0;
        rep(j,n) mx = max(mx,cnt[n-1-j]);
        ans = min(ans, mx);
    }
    printf("%d\n",ans);
}