wa,ba=map(int,input().split())
wb,bb=map(int,input().split())
a,b=map(int,input().split())
if a-ba>=0:
    wa-=a-ba
    wb+=a-ba
    if wb<b:
        wa+=wb
    else:
        wa+=b
else:
    if wb<b:
        wa+=wb
    else:
        wa+=b
print(wa)