let d = [| 31; 28; 31; 30; 31; 30; 31; 31; 30; 31; 30; 31 |] in
let count m d =
    let rec loop i acc =
        if i = 0 then acc else
            let acc = if i / 10 + (i mod 10) = m then acc + 1 else acc in
            loop (i - 1) acc
    in
    loop d 0
in
let rec loop_m m acc =
    if m = 12 then acc else
        loop_m (m + 1) (acc + count (m + 1) d.(m))
in
loop_m 0 0 |> Printf.printf "%d\n"