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
from collections import defaultdict
string=input()
l=1
r=len(string)

def check(mid):
    i=0
    memo=defaultdict(int)
    find=defaultdict(int)
    j=0
    while j<len(string):
        if j-i<mid:
            memo[string[j]]+=1
            if temp==0:
                find[string[j]]=1
            j+=1
        else:
            memo[string[i]]-=1
            if memo[string[i]]==0 and string[j]!=string[i]:
                find[string[i]]=0
            i+=1
    for val in find:
        if find[val]==1:
            return True
    return False
   

while l<=r:
    mid=(l+r)//2
    if check(mid):
        r=mid-1
        temp=mid
    else:
        l=mid+1
    
print(temp)
