enigma

let rec find (max_age, min_age) =
  let answer = (max_age, min_age) in
  if is_valid_answer answer then answer
  else
    if min_age <= max_age
    then
      let new_max = (max_age - 1, min_age) in
      if is_valid_answer new_max then new_max
      else
        let new_min = (max_age - 1, min_age + 1) in
        find new_min
    else
      (-1, -1);;