n=gets.to_i-1
a,b=$<.map{|e|e.split.map &:to_i}.transpose
sa,sb=[a,b].map(&:sum)
if sa<sb
	a,b=b,a
	sa,sb=sb,sa
end
p (0..100).find{|x|
	y=x+sa-sb
	not (y<=sa && (0...n).all?{|i|
		a[i]+b[i]<=x+sa
	})
}