a,b=gets.split.map{|i|'%020d'%i}
r=0
20.times.any?{|i|x,y=a[i],b[i]
z=x<=>y
[x,y].sort==[?4,?7]?r=-z:z!=0?r=z:p}
$><<[0,a,b][r].to_i