7.10 Find a minimum two-level, multiple-output AND-OR gate circuit to realize these functions. f1(a,b,c,d)=m(3,4,6,9,11)f2(a,b,c,d)=m(2,4,8,10,11,12)f3(a,b,c,d)=m(3,6,7,10,11) (11 gates minimum)