behe

defmodule ATGCCount do
  def count(sequence), do: cnt(String.to_char_list(sequence),0,0)
  def cnt([65|t],at,gc), do: cnt(t,at+1,gc)
  def cnt([84|t],at,gc), do: cnt(t,at+1,gc)
  def cnt([71|t],at,gc), do: cnt(t,at,gc+1)
  def cnt([67|t],at,gc), do: cnt(t,at,gc+1)
  def cnt([62|_],at,gc), do: {at,gc}
  def cnt([],at,gc), do: {at,gc}
  # def cnt(_,0,0), do: {0,0}
  def cnt([_|t], at, gc), do: cnt(t,at,gc)