Aw,Ab = map(int,input().split())
Bw,Bb = map(int,input().split())
C,D =map(int,input().split())

mw,mb = (C-min(Ab,C)),min(Ab,C)
Aw,Ab = Aw-mw,Ab-mb
Bw,Bb = Bw+mw,Bb+mb
mw,mb = min(Bw,D),D-min(Bw,D)
Aw,Ab = Aw+mw,Ab+mb
print(Aw)