#! ruby
# yukicoder My Practice
# author: Leonardone @ NEETSDKASU

aw, ab, bw, bb, c, d = $<.flat_map{|x| x.split.map(&:to_i)}

if c > ab
	aw -= c - ab
	bw += c - ab
	bb += ab
else
	bb += c
end

if d < bw
	aw += d
else
	aw += bw
end

puts aw