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

INF = 10**18
dp = [[-INF]*(K+1) for _ in range(2)]
dp[0][0] = 0
for a in A:
    ndp = [[-INF]*(K+1) for _ in range(2)]
    for k in range(K+1):
        ndp[0][k] = max(dp[0][k], dp[1][k])
        if k and dp[0][k-1] != -INF:
            ndp[1][k] = max(ndp[1][k], dp[0][k-1] + a)
    dp = ndp
ans = max(dp[0][K], dp[1][K])
print('Impossible' if ans==-INF else ans)