import itertools
from copy import deepcopy
from functools import cache
import sys
sys.setrecursionlimit(10 ** 9)
import math
from collections import Counter, deque
input = lambda: sys.stdin.readline().rstrip()
mod = 998244353

n, k = map(int, input().split())
a = list(map(int, input().split()))

now_dp = [[-math.inf, -math.inf] for _ in range(k + 1)]
now_dp[0][1] = 0

# print(dp)

for i in range(n):
    # print(now_dp)
    for j in range(k, 0, -1):
        now_dp[j][1] = max(now_dp[j][1], now_dp[j][0])
        now_dp[j][0] = now_dp[j - 1][1] + a[i]

if max(now_dp[-1]) == -math.inf:
    print("Impossible")
else:
    print(max(now_dp[-1]))