let rec tak (x, y, z) =
  if x > y then tak(tak (x-1, y, z), tak (y-1, z, x), tak (z-1, x, y))
           else z

let rec repeat n =
  if n <= 0 then 0 else tak(18,12,6) + repeat(n-1)

let _ = print_int (repeat 50); print_newline(); exit 0