n,k=map(int,input().split())
a=list(map(int,input().split()))
dp=[[[-10**18,-10**18] for _ in range(k+1)]for _ in range(n+1)]
dp[0][0][0]=0 
for i in range(n):
	for j in range(k+1):
		if j<k:
			dp[i+1][j+1][1]=max(dp[i+1][j+1][1],dp[i][j][0]+a[i])
		dp[i+1][j][0]=max(dp[i+1][j][0],dp[i][j][0],dp[i][j][1])
ans=max(dp[-1][-1])
if ans<-10**15:
	print('Impossible')
else:
	print(ans)