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

    a = {'w': Aw, 'b': Ab}
    b = {'w': Bw, 'b': Bb}

    bk = a['b'] - C
    if bk < 0:
        a['w'] += bk
        b['w'] -= bk

    wt = b['w'] - D
    if wt < 0:
        a['w'] += b['w']
    else:
        a['w'] += D

    print(a['w'])

main()