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
s = input()
r = 100000
l = 0
dictC = {}
setC = set()
for i in range(97, 97 + 26):
    setC.add(chr(i))
    dictC.update({chr(i): 0}) 

def seach(k, setC, dict1):
    for i in range(0, len(s)):
        dict1[s[i]] += 1         
        if i >= k - 1:
            if i != k - 1:
                dict1[s[i - k]] -= 1
            set2 = set()
            for z in setC:
                if dict1[z] != 0:
                    set2.add(z)
            setC = set2
            if len(setC) == 0:
                return 0
    return 1

while r - l > 1:
    mid = (r + l) // 2
    for i in range(97, 97 + 26):
        dictC.update({chr(i): 0})    
    if seach(mid, setC, dictC) == 1:
        r = mid
    else:
        l = mid
print(r)
    
