a1, a2, a3, b = map(int, input().split())
a = [a1, a2, a3]
ans = 0
for i in range(3):
    for j in range(3):
        for k in range(3):
            ans = a[i] + a[j] + a[k]

ans = max(ans, sum(a)+b)
print(ans)