A full adder circuit can be used to count the number of 1s in a three bit unsigned number. For example, if the number is 101, we can find the number of 1s in this three bit number by just adding its bits (1+0+1=10). Two of the bits will be applied to the inputs of the full adder and the third bit will be applied to its Cin input. Now, we want to build a circuit that counts the number of 1s in a 6-bit unsigned numbers using full and half adder circuits as building blocks. Design the simplest circuit that can accomplish this task.