output_description: Print `Yes` if the string `CF` can be obtained from the string s by deleting
  some characters. Otherwise print `No`.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      s
attempt: import sys
  
  
  def LI():
      return list(map(int, sys.stdin.buffer.readline().split()))
  
  
  def I():
      return int(sys.stdin.buffer.readline())
  
  
  def LS():
      return sys.stdin.buffer.readline().rstrip().decode("utf-8").split()
  
  
  def S():
      return sys.stdin.buffer.readline().rstrip().decode("utf-8")
  
  
  def IR(n):
      return [I() for i in range(n)]
  
  
  def LIR(n):
      return [LI() for i in range(n)]
  
  
  def SR(n):
      return [S() for i in range(n)]
  
  
  def LSR(n):
      return [LS() for i in range(n)]
  
  
  def SRL(n):
      return [list(S()) for i in range(n)]
  
  
  def MSRL(n):
      return [[int(j) for j in list(S())] for i in range(n)]
  
  
  s = S()
  ans = ""
  if "C" in s:
      ans += "C"
  if "F" in s[s.index("C") :]:
      ans += "F"
  if ans == "CF":
      print("Yes")
  else:
      print("No")
  
problem_description: Statement
  
  This contest is `CODEFESTIVAL`, which can be shortened to the string `CF` by
  deleting some characters.
  
  Mr. Takahashi, full of curiosity, wondered if he could obtain `CF` from other
  strings in the same way.
  
  You are given a string s consisting of uppercase English letters. Determine
  whether the string `CF` can be obtained from the string s by deleting some
  characters.
samples: [{"input": "CODEFESTIVAL", "output": "Yes\n    \n\n`CF` is obtained by deleting characters other than the first character `C` and\nthe fifth character `F`.\n\n* * *"}, {"input": "FESTIVALCODE", "output": "No\n    \n\n`FC` can be obtained but `CF` cannot be obtained because you cannot change the\norder of the characters.\n\n* * *"}, {"input": "CF", "output": "Yes\n    \n\nIt is also possible not to delete any characters.\n\n* * *"}, {"input": "FCF", "output": "Yes\n    \n\n`CF` is obtained by deleting the first character."}]