function Maxdigit(var L: list): integer;
var Max1:Integer;
    function Max2(x1,x2:integer): integer;
        begin
            if (x1>=x2) then
        Max2:=x1
      else
        Max2:=x2;
        end;
begin
  if (L<>nil) then
    if (L^.next=nil) then
      Maxdigit:=l^.elem
    else
      Maxdigit:=max2(L^.elem,Maxdigit(L^.next));
end;