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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using db = double;
#define fi first
#define se second
#define pb push_back
#define all(v) (v).begin(),(v).end()
#define siz(v) (int)(v).size()
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define repn(i,n) for(ll i=0;i<=(ll)(n);i++)
typedef pair<int,int> P;
typedef pair<ll,ll> PL;
const ll mod = 1000000007;
const ll INF = 1000000099;
//cin.tie(0);
//ios::sync_with_stdio(false);



signed main(){
    string s;cin>>s;
    int ans=110;

    for (char i = 'a'; i < 'z'+1; i++)
    {
        int left=-1,subans=0;

        for(int j=0;j <= siz(s);j++)
        {
            if(j==siz(s)){
                subans=max(subans,siz(s)-left-1);
            }else if(s[j]==i){
                subans=max(subans,j-left-1);
                left=j;
            }
        }
        ans=min(ans,subans);
    }
    cout<<ans<<endl;
}