A bank has 3 locks with a key for each lock. Each key is owned by a different person. In order to open the vault door at least two people must insert their keys into the assigned locks at the same time. The trainee (i.e. person C) can only open the vault when the manager (i.e. person A) is present in the opening. The signal lines (A,B,C) are 1 if the key is inserted into locks 1,2,3 respectively. ? Determine the truth table for such a digital locking system. ? Implement the minimal circuit found in the previous section using by drawing; 1 Two input NAND gates only. 2 Two input NOR gates only.