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

dp0 = [-inf] * (K+1)
dp1 = [-inf] * (K+1)
dp0[0] = 0

for i in range(N):
    od0 = [-inf] * (K+1)
    od1 = [-inf] * (K+1)
    od0, dp0 = dp0, od0
    od1, dp1 = dp1, od1
    for k in range(K+1):
        dp0[k] = max(od0[k], od1[k])
        dp1[k] = od0[k-1] + A[i]

ans = max(dp0[K],dp1[K])
if ans == -inf:
    print("Impossible")
else:
    print(ans)