Imports System.Console
Module Program
 	Sub Main()
	    Dim s As String= Console.ReadLine()

	    Dim n As Integer = Len(s)

	    Dim indexOfC As Integer = inStr(s, "C")
	    Dim indexOfF As Integer = inStr(indexOfC, s, "F")

        Console.WriteLine(IIF(indexOfC>=1 And indexOfF >=1 And indexOfC<indexOfF, "Yes", "No"))
    End Sub
End Module
