The Company manufactures paring knives and pocket knives. Each paring knife requires 3 labor-hours, 7 units of steel, and 4 units of wood. Each pocket knife requires 6 labor-hours, 5 units of steel, and 3 units of wood. The prot on each paring knife is $3, and the prot on each pocket knife is $5. Each day the company has available 78 labor-hours, 137 units of steel, and 132 units of wood. Suppose that the number of labor-hours that are available each day is increased by h. For what values of h will a change of h labor-hours not change the shadow price of labor? The shadow price of labor will not change for S h s (Simplify your answers.)