Scanf.scanf "%d %d %d %d" (fun a b c d ->
    let rec loop taka aoki turn =
        if turn then (
            let aoki = aoki - b in
            if aoki > 0 then loop taka aoki false else "Yes"
        ) else (
            let taka = taka - d in
            if taka > 0 then loop taka aoki true else "No"
        )
    in
    print_endline @@ loop a c true
)