program main
implicit none
character(len=100) :: s
integer :: i, j
logical :: status

read(*,*) s
status = .false.

do i = 1, len_trim(s)
if ( s(i:i) == 'C' ) then
j = i
exit
end if
end do

do i = j+1, len_trim(s)
if ( s(i:i) == 'F' ) then
status  = .true.
exit
end if
end do

if (status) then
write(*,'(a)') 'Yes'
else
write(*,'(a)') 'No'
end if

stop
end program main
