Adder 2

Now go one level deeper in the hierarchy. The same 32-bit adder is built from two add16 modules — but this time add16 is a structural adder that instantiates sixteen 1-bit full adders named add1:

module add1 ( input a, input b, input cin, output sum, output cout );

You must write two things:

1. top_module — instantiate two of the provided add16 modules to form a 32-bit adder, exactly as in the previous exercise (lower half gets cin = 0; its cout feeds the upper half's cin; final cout is dropped).
2. The full adder add1 itself. A full adder adds three 1-bit values and produces a 2-bit result:

sum  = a XOR b XOR cin
cout = majority(a, b, cin)  —  at least two of the three inputs are 1

The provided add16 (below your code) chains your add1 sixteen times via a ripple-carry — don't modify it. If add1 is wrong, the whole adder is wrong.