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

Cb = min(C, Ab)
Cw = C - Cb

Aw -= Cw
Ab -= Cb

Bw += Cw
Bb += Cb

Dw = min(D, Bw)
Db = Bw + Bb - Dw

print(Aw + Dw)