s1=s2=8*8/4=16;s3=8*(8/2)*(3/4)*(1/2)*(1/3)=4;s4=8*(8/2)*(3/4)*(1/2)*(1/3)=8;s5=8*(8/2)*(3/4)*(1/2)*(1/3)=4;s6=8*(8/2)*(3/4)*(1/2)*(2/3)=8;s7=8*(8/2)*(1/4)=8;