import Complex m@main=getLine>>=print.i.map read.words>>m i[a,b,c,d,e,f,g,h]=j[a:+b,c:+d,e:+f,g:+h] j[s,t,u,v]=sum[1|0>y p*y(p/(s-v)*(t-v))]where y=imagPart;p=(s-u)/(t-u)