module Split = struct
let rec str_split str spchar =
    match str with
    | "" -> []
    | str ->
            try
                let spchar_index = String.index str spchar in
                let substr = String.sub str 0 spchar_index in
                if (spchar_index + 1) == (String.length str)
                then [substr]
                else
                    let rest = String.sub str (spchar_index + 1) ((String.length str) - spchar_index - 1) in
                    substr::(str_split rest spchar)
            with
                 Not_found -> [str]
                | Invalid_argument e -> []
end

let _ =
    let instr = read_line () in
    let instrlist = Split.str_split instr ' ' in
    let x = int_of_string (List.hd instrlist) in
    let y = int_of_string (List.hd (List.tl instrlist)) in
    print_int (x + (y / 2));
    print_newline ();
