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.
def main():
    s = input()
    a = s.index('C')
    if a and 'F' in s[a+1:]:
        print('Yes')
    else:
        print('No')

main()

def main():
    s = input()
    if 'C' in s and 'F' in s[s.index('C')+1:]:
        print('Yes')
    else:
        print('No')

main()
