from itertools import permutations

N, K, X = map(int, input().split())
A = list(map(int, input().split()))

max_ = -100000000000

i = 1

while i <= N:
    L = set(permutations(A[:i], min(i, K)))
    for l in L:
        max_ = max(sum(l) - i * X, max_)
    i += 1

print(max_)