{ > Src.Ack }

program acker (output);

var now : integer;

function ack (x, y : integer) : integer;
begin
  if x=0
    then ack := y+1
    else if y = 0
           then ack := ack (x-1, 1)
           else ack := ack (x-1 , ack (x, y-1))
end;

begin
  now := time;
  writeln ('ack (3,4) is ', ack (3, 4), ', ', time-now, ' centiseconds')
end.