c = [0] * 27
for i in range(1, 27):
    c[i] = int(input())

res = c[4] * c[5] * c[8] * (c[15] // 2) * (c[15] - c[15] // 2) * c[18] * c[23]
if c[12] >= 3:
    comb_max = 0
    for l_world in range(1, c[12] - 2 + 1):
        l_hello = c[12] - l_world
        comb = (l_hello * (l_hello - 1) // 2) * l_world
        comb_max = max(comb, comb_max)
    res *= comb_max
else:
    res = 0

print(res)