Every person convicted of a felony for which no maximum punishment is specially prescribed by any statutory provision in force at the time of conviction and sentence, shall be punished by confinement or fine which shall not exceed confinement in a state correctional institution for a term of ten years, or by a fine in an amount fixed by the court of not more than twenty thousand dollars, or by both such confinement and fine and the offense shall be classified as a class B felony.