(**
   Xstring
*)
let isub str i1 i2 =
  try String.sub str i1 (i2-i1+1)
  with Invalid_argument("String.sub") -> 
    raise (Invalid_argument("Xstring.isub"))



(**
   line format: '== +[a-z]+.?[a-z]* +[A-E][\+-]?'
*)
let parse_line line =
  let name1 = ref "" 
  and name2 = ref "" in
  let mark = ref "" in
  let a = int_of_char 'a'
  and z = int_of_char 'z' in
  let is_a_z c = 
    let c = int_of_char c in
      (a <= c) && (c <= z)
  in
  let len = String.length line in
  let i = ref 0 in
  let i0 = ref 0 in
    while (line.[!i] = '=' || line.[!i] = ' ')  do incr i done;
    i0 := !i;
    while (is_a_z line.[!i]) do incr i done;
    name1 := isub line !i0 (!i-1);
    if (line.[!i] = '.') then (
      incr i;
      i0 := !i
    );
    i0 := !i;
    while (!i < len) && (is_a_z line.[!i]) do incr i done;
    if (!i > !i0) then name2 := isub line !i0 (!i-1);
    while (line.[!i] = ' ')  do incr i done;
    if (!i+1 < len) then mark := isub line !i (!i+1)
    else mark := isub line !i !i;
    (!name1, !name2,!mark)

let marks = ref []

let add_mark numtp name mark =
  try 
    let ms = List.assoc name !marks in
      ms.(numtp) <- mark
  with
      Not_found -> (
	let ms = Array.create 6 0 in
	  ms.(numtp) <- mark;
	  marks := (name, ms)::!marks
      )
  
let mark_of_alpha m =
  let n =
    match m.[0] with
	'A' -> 13
      | 'B' -> 10
      | 'C' -> 7
      | 'D' -> 4
      | 'E' -> 0
      | _ -> failwith ("mark_of_alpha: not an alpha mark "^m)
  in
    if (String.length m) > 1 then
      if m.[1] = '+' then n+1
      else n-1
    else n
;;

let numtp = ref (-1) in
let ic = open_in Sys.argv.(1) in
  try
    while true do
      let line = input_line ic in
	if String.length line > 2 then (
	  if (line.[0] = '=') then (
	    if (line.[2] = '=') then (
	      incr numtp
	    )
	    else (
	      match parse_line line with
		  name, "", mark -> add_mark !numtp name (mark_of_alpha mark)
		| name1, name2, mark -> (
		    add_mark !numtp name1 (mark_of_alpha mark);
		    add_mark !numtp name2 (mark_of_alpha mark)
		  )
	    )
	  )
	)
    done
  with
      End_of_file -> (
	List.iter
	  (fun (name, ms) ->
	     Printf.printf"%s " name;
	     Printf.printf"%.2f\n"
	       ((float_of_int (Array.fold_right (+) ms 0))
		/. (float_of_int (Array.length ms)))
	  )
	  (List.sort compare !marks);
	close_in ic
      )