PROCEDURE GetFuelNeededForTrajectory*(distance: LONGINT; plane: Airplane.Airplane): LONGINT;

        VAR
            fuel: LONGINT;
    BEGIN
        IF plane IS Airliner.Airliner THEN
            RETURN distance;
        ELSIF plane IS Cargoplane.Cargoplane THEN
            fuel := distance * 2;
            RETURN fuel;
        ELSE
            Out.String("Fail.");
            Out.Ln();
        END;
    END GetFuelNeededForTrajectory;