#include<bits/stdc++.h>
using namespace std;
string str;

int main(){
	cin>>str;
	int f=0;
	for(int i=0;i<str.length();i++){
		if(str[i]=='C')f=1;
		if(f==1&&str[i]=='F'){f=2;break;}
	}
	if(f==2)cout<<"Yes";
	else cout<<"No";
	return 0;
}