open System

let s = Console.ReadLine()

let cindex = Seq.tryFindIndex (fun x -> x = 'C') s
match cindex with
| None -> printfn "No"
| Some i -> begin
              match Seq.tryFindIndex (fun x -> x = 'F') (s.[i..Seq.length s-1]) with
              | None -> printfn "No"
              | _ -> printfn "Yes"
            end