INF = 2 * 10**18
inf = 10**18

def f(is_deleted, times):
    return 2 * times + is_deleted


N, K = [int(s) for s in input().split()]
A = [int(s) for s in input().split()]

dp = [-INF] * (2 * (K + 1))
dp[f(0, 0)] = 0

for a in A:
    ndp = [-INF] * (2 * (K + 1))

    for k in range(K + 1):
        ndp[f(0, k)] = max(ndp[f(0, k)], dp[f(0, k)], dp[f(1, k)])
        if k >= 1:
            ndp[f(1, k)] = max(ndp[f(1, k)], dp[f(0, k - 1)] + a)

    dp = ndp

ans = max(dp[f(0, k)], dp[f(1, k)])
print(ans if ans > -inf else "Impossible")