Scanf.scanf "%d" (fun n -> let items = Array.make 10 0 in for i = 1 to n do Scanf.scanf " %d %d %d" (fun a b c -> items.(a - 1) <- items.(a - 1) + 1; items.(b - 1) <- items.(b - 1) + 1; items.(c - 1) <- items.(c - 1) + 1; ) done; let rec loop i r acc = if i = 10 then acc + r / 4 else loop (i + 1) (r + items.(i) mod 2) (acc + items.(i) / 2) in loop 0 0 0 |> Printf.printf "%d\n" )