a1,a2=map(int,input().split())
b1,b2=map(int,input().split())
c,d=map(int,input().split())
x1=max(c-a2,0);x2=min(a2,c)
a1-=x1;a2-=x2
b1+=x1;b2+=x2
print(a1+min(d,b1))