output_description: Output an integer representing the minimum number of iterations needed for the
  rewrite operation.
  
  * * *
input_description: Inputs are provided from Standard Input in the following form.
  
      
      
      S
attempt: s=input()
  ans=0
  if s[0]=='C':
      ans+=1
  if s[1]='O':
      ans+=1
  if s[2]='D':
      ans+=1
  if s[3]='E':
      ans+=1
  if s[4]='F':
      ans+=1
  if s[5]='E':
      ans+=1
  if s[6]='S':
      ans+=1
  if s[7]='T':
      ans+=1
  if s[8]='I':
      ans+=1
  if s[9]='V':
      ans+=1
  if s[10]='A':
      ans+=1
  if s[11]='L':
      ans+=1
  if s[12]='2':
      ans+=1
  if s[13]='0':
      ans+=1
  if s[14]='1':
      ans+=1
  if s[15]='6':
      ans+=1
  print(ans)
problem_description: Statement
  
  CODE FESTIVAL 2016 is going to be held. For the occasion, Mr. Takahashi
  decided to make a signboard.
  
  He intended to write `CODEFESTIVAL2016` on it, but he mistakenly wrote a
  different string S. Fortunately, the string he wrote was the correct length.
  
  So Mr. Takahashi decided to perform an operation that replaces a certain
  character with another in the minimum number of iterations, changing the
  string to `CODEFESTIVAL2016`.
  
  Find the minimum number of iterations for the rewrite operation.
samples: [{"input": "C0DEFESTIVAL2O16", "output": "2\n    \n\nThe second character `0` must be changed to `O` and the 14th character `O`\nchanged to `0`.\n\n* * *"}, {"input": "FESTIVAL2016CODE", "output": "16"}]