Input (grade 8): In the United States and Canada the standard lengths of lumber are 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 feet.
Output (grade 6): In the United States the standard lengths of lumber are 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 feet.