aw,ab=map(int,input().split())
bw,bb=map(int,input().split())
c,d=map(int,input().split())
if aw<=ab and ab<c:
    bw+=(c-ab)
    aw-=(c-ab)
if ab==0:
    bw+=c
    aw-=c
if bw<=d:
    aw+=bw
if d<=bw:
    aw+=d
print(aw)