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

    if Ab < C:
        transfer_A_white = C - Ab
        Aw = Aw - transfer_A_white
        Bw = Bw + transfer_A_white

    if Bw < D:
        print(Aw + Bw)
    else:
        print(Aw + D)


if __name__ == '__main__':
    main()