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 <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <stack>
#include<algorithm>
#include<sstream>
#include<iomanip>
#include<deque>
#include<list>


using namespace std;

typedef long long ll;

typedef pair<int, int> pii;

const ll MOD_CONST = 1000000007;
const ll BIG_NUM = 1000000000000000000;
const int BIG_INT = 1000000000;

int main() {
	string s;
	cin >> s;

	int ans = s.length();
	for (char c = 'a'; c <= 'z'; c++) {
		int maxLen = 0;
		int cnt = 0;
		for (int i = 0; i < s.length();i++) {
			if (s[i] == c) {
				maxLen = max(maxLen, cnt);
				cnt = 0;
			}
			else {
				cnt++;
			}
		}

		maxLen = max(maxLen, cnt);

		ans = min(ans, maxLen);
	}

	cout << ans << endl;
}