let read_int () = Scanf.scanf " %d" (fun x -> x);; let n = read_int ();; let a = Array.init n (fun _ -> read_int ());; let all = ref true;; for i = 0 to n - 2 do if a.(i) + 1 >= a.(i + 1) then all := false done;; print_endline (if !all then "1" else "2");;