#include<iostream>
using namespace std;
string s;int i,g=0;
int main()
{
	cin>>s;
	for(i=0;i<s.size();i++)if(s[i]=='C')break;
	for(;i<s.size();i++)if(s[i]=='F'){g=1;break;}
	if(g)cout<<"Yes";
	else cout<<"No";
}