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