def ris() gets.split.map &:to_i end
def ri() gets.to_i end
MOD = 1_000_000_007 # 998_244_353
aw,ab=ris
bw,bb=ris
c,d=ris
mn=[c,ab].min
c,ab,bb=c-mn,ab-mn,bb+mn
aw,bw=aw-c,bw+c
p [d,bw].min+aw