N,K = map(int, input().split())
a = [0]+list(map(int, input().split()))

dp = [[[-9223372036854775807, -9223372036854775807] for j in range(K+1)] for i in range(N+1)]

for i in range(N+1):
	dp[i][0][0] = 0
	dp[i][0][1] = 0
for i in range(1, N+1):
	for j in range(1, K+1):
		# これを取る。
		dp[i][j][1] = max(dp[i][j][1], dp[i-1][j-1][0]+a[i])
		# これを取らない
		dp[i][j][0] = max(dp[i][j][0], dp[i-1][j][0], dp[i-1][j][1])

# print(dp)
ans = -9223372036854775807
for i in range(1, N+1):
	ans = max(ans, dp[i][K][0], dp[i][K][1])
if ans < -922337203685477580:
	print("Impossible")
else:
	print(ans)
# print(dp)