program AgilaStudy;
{$mode objfpc}{$H+}{$assertions on}
function Remaining(Total, Done: Integer): Integer;
begin
  if Done >= Total then Result := 0 else Result := Total - Done;
end;

begin
  Assert(Remaining(4,1)=3);
  Assert(Remaining(4,4)=0);
  Assert(Remaining(4,5)=0);
  Assert(Remaining(0,0)=0);
  writeln('Nipasar');
end.