L = list(map(int,input().split()))
R = list(map(int,input().split()))
L2 = []
for i in range(3):
    L2.append(L[i]+L[(i+1)%3])
L2.sort()
R.sort(reverse = True)
ans = 0
for i in range(3):
    ans += L2[i] * R[i]
ans *= 2
print(ans)