The product structure for Item X specifies the required number of units for each constituent part within parentheses. (Note that 4 units of part C are required for X and one unit of part C by B.) Level 0 X Level 1 * Level 2 C (1) Part B C D H K M N X Z K (1) B (1) Lead Time (in weeks) 2 1 3 2 3 2 3 2 3 D (2) H (1) N (1) The lead times for manufacturing any number of the following components given the the following table: Z (2) M (2) C (4) H (1) K (1) There is no inventory on hand and the order for Item X is to be shipped at the beginning of week 10. In what week will manufacture of part K start? Specify only the number..