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