n, h, w = map(int, input().split())
if h < w:
    h, w = w, h
if h == w == 1:
    print(0)
elif w == 1:
    n1 = n // 2
    n2 = n - n1
    h -= 1
    print(n1 * n2 * h)
else:
    q, r = divmod(n, 4)
    h -= 1
    w -= 1
    if r == 0:
        print(q * q * 2 * (h + w) + q * q * 2 * (h + w))
    elif r == 1:
        print((q * q + q * (q + 1)) * (h + w) + (q * (q * 1) + q * q) * (h + w))
    elif r == 2:
        print(((q + 1) * (q + 1) + q * q) * (h + w) + q * (q + 1) * 2 * (h + w))
    else:
        print(((q + 1) * (q + 1) + (q + 1) * q) * (h + w) + ((q + 1) * (q + 1) + (q + 1) * q) * (h + w))