#include<bits/stdc++.h>
using namespace std;
string a;bool flag;
int main()
{
	cin>>a;
	for(int i=0;i<a.size();i++)
	{
		if(a[i]=='C')flag=true;
		if(a[i]=='F')
			if(flag)puts("Yes"),exit(0);
			else continue;
	}
	puts("No");return 0;
}