aw,ab=map(int,input().split())
bw,bb=map(int,input().split())
c,d=map(int,input().split())
tmp1=min(c,ab)
tmp2=max(0,c-tmp1)
aw-=tmp2
bb+=tmp1;bw+=tmp2
aw+=min(d,bw)

# print("A:",bw,bb)
print(aw)