program ackermann;

(for m in [0..3])
  print(+/ [rpad('' + ack(m, n), 4): n in [0..6]]);
end;

proc ack(m, n);
  return {[0,n+1]}(m) ? ack(m-1, {[0,1]}(n) ? ack(m, n-1));
end proc;

end program;