character(100) S
int check
read*S
check=0
do i=1,len_trim(S)
  if(check==0)then
    if(S(i:i)=="C")check=1
  else if(check==1)then
    if(S(i:i)=="F")check=2
  end if
end do
print"(A)",merge("Yes"," No",check==2)
end
  