You are given a string *s* consisting of lowercase Latin letters. Character *c* is called *k*-dominant iff each substring of *s* with length at least *k* contains this character *c*.

You have to find minimum *k* such that there exists at least one *k*-dominant character.
The first line contains string *s* consisting of lowercase Latin letters (1 ≤ |*s*| ≤ 100000).
none
abacaba
2
zzzzz
1
abcde
3
bcaccacaaabaacaabaaabcbbcbcaacacbcbaaaacccacbbcbaabcbacaacbabacacacaccbbccbcbacbbbbccccabcabaaab
8
daabcdabbabbacacbaacabacbcaabaacac
4
abghim
4
gfliflgfhhdkceacdljgkegmdlhcgkcmlelmbbbmdddgdeeljjhgbbffmemmmkhebgkhadkdajabcjkcgbkgbaeacdedlkklfech
17
a
1
aaabbb
4
ab
2
abbb
2
ob
2
abccba
3
saaaaaaaas
2
axxx
2
abcba
2
abb
2
abcdea
4
axcbb
3
tmivvdcbbfrfogjviirrximhttoskopwrcmkcborcxvr
13
dlchmmuateksgldkckljrovmeuniobjrelqjpnjljlvhpqrjsfklliqpufplgaelevmlcnodbllquubobecem
15
zx
2
zxz
2
bbhdgaefbhf
6
xx
1
zxx
2
cbcada
4
z
1
aab
2
jficc
3
cceeaabfba
5
jk
2
lzeznbwu
5
rr
1
def getCharacters(s):
    res = {}
    for l in s:
        res[l] = 0
    return res

def minKValue(chr, s, lenS, k=2):
    while k <= lenS:
        chr = getCharacters(s)
        window = [0, k]
        qtdParts = lenS - k + 1
        while window[1] <= lenS:
            subs = s[window[0]:window[1]]
            letters = set()
            #print("substring: {}".format(subs))
            for letter in subs:
                if letter not in letters:
                    chr[letter] += 1
                    letters.add(letter)
            window[0] += 1
            window[1] += 1
        #print("map: {}".format(chr))
        for char in chr.keys():
            if chr[char] == qtdParts:
                return k
        k += 1
    return k

def process(s, lenS):
    characters = getCharacters(s)
    if lenS == 1 or len(characters.keys()) == 1:
        return 1
    else:
        return minKValue(characters, s, lenS)

def run():
    s = input()
    lenS = len(s)
    minK = process(s, lenS)
    print(minK)

#print(getCharacters('stesctsc'))
run()