s1=(1/4)^2*s=s/16
s2=(1/2)^2*s-s1=3s/16.
s3=(3/4)^2*s-(s1+s2)=5s/16.
s4=s-(s1+s2+s3)=7s/16.
S1:S2:S3:S4=1:3:5:7