import math
import sys
def S(): return sys.stdin.readline().rstrip()
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int, sys.stdin.readline().rstrip().split())
def LI(): return list(map(int, sys.stdin.readline().rstrip().split()))
def LS(): return list(sys.stdin.readline().rstrip().split())

aw, ab = MI()
bw, bb = MI()
c, d = MI()

if ab <= c:
    bw = bw + (c - ab)
    bb = bb + ab
    aw = aw - (c - ab)
    ab = 0
else:
    bb = bb + c
    ab = ab - c

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

print(aw)