#!/bin/bash

read s

char_count=$(echo ${s} | wc -c)

if [ ${char_count} -lt 2 -o ${char_count} -gt 1001 ]; then
  exit
fi

echo "${s}" | egrep ".*C.*F.*" > /dev/null
if [ $? -eq 0 ]; then
  echo "Yes"
else
  echo "No"
fi