main::IO()
main = do
  str<-getLine
  putStr (b_to_YN (solver str))
  putStr "\n"

solver::String -> Bool
solver []     = False
solver (c:cs) = if c == 'C' then subsolver cs else solver cs

subsolver::String ->Bool
subsolver []     = False
subsolver (c:cs) = if c == 'F' then True else subsolver cs

b_to_YN::Bool -> String
b_to_YN b = if b then "Yes" else "No"