def chmax(DP,i,v):
    if DP[i] < v: DP[i] = v
def chmin(DP,i,v):
    if DP[i] > v: DP[i] = v

INF = 1e18
N, K = map(int, input().split())

if K > (N + 1)//2:
    exit(print('Impossible'))

A = list(map(int, input().split()))

dp = [[[-INF] * (2) for _ in range(K + 1)] for _ in range(N + 1)]
dp[0][0][1] = 0

for i in range(N):
    a = A[i]
    for j in range(K + 1):
        for k in range(2):
            if dp[i][j][k] == -INF:
                continue

            # 不採用（削除しない）
            # dp[i + 1][j][k|1]
            chmax(dp[i + 1][j], k|1, dp[i][j][k])

            # 採用（削除）
            # dp[i + 1][j + 1][0]
            if k == 1 and j + 1 <= K:
                chmax(dp[i + 1][j + 1], 0, dp[i][j][k] + a)

ans = max(dp[-1][-1])
print(ans)