n, k = list(map(int, input().split()))
A = list(map(int, input().split()))
inf = 1<<60
dp0 = [-inf] * n
dp1 = [-inf] * n
dp0[0] = 0
for a in A:
    ndp0 = [-inf] * n
    ndp1 = [-inf] * n
    for i in range(k):
        ndp1[i+1] = dp0[i]+a
    for i in range(k+1):
        ndp0[i] = max(dp0[i], dp1[i])
    dp0, dp1 = ndp0, ndp1
ans = max(ndp0[k], ndp1[k])
if ans < -(1<<50):
    print("Impossible")
else:
    print(ans)