4 bit adder - Reuploaded

4 bit adder this is messy but I have improved: inputs on left and outputs on right List: 0000-0 0001-1 0010-2 0011-3 0100-4 0101-5 0110-6 0111-7 1000-8 1001-9 1010-10 1011-11 1100-12 1101-13 1110-14 1111-15 most complex yet