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
a = input()

symbols = []
len_symbols = []
for i in a:
  if i in symbols :
    ii = symbols.index(i)
    len_symbols[ii]+=1
  else:
    symbols.append(i)
    len_symbols.append(1)
  # if a.count(a[i]) > y:
  #   x = a[i]
  #   y = a.count(a[i])
    
q = []
y = max(len_symbols)
x = a[y]

if y > 1:

  for  i in range(0,len(a)):
    if a[i] == x:
      q.append(i)
      
      
  b = max(q)
  
  
  for i in range(1,len(q)-1):
    if q[i]-q[i-1] < b:
      b = q[i]-q[i-1]
  print(b)

else:
  print((len(a)+1)//2)
  