aw,ab,bw,bb,c,d=gets(p).split.map(&:to_i)
minb=[ab,c].min
c-=minb
ab-=minb
bb+=minb
if c>0
	aw-=c
	bw+=c
end
minw=[bw,d].min
d-=minw
bw-=minw
aw+=minw
if d>0
	bb-=d
	ab+=d
end
p aw