import sys
import math
input = sys.stdin.readline
N, K = map(int, input().split())
A = list(map(int, input().split()))
NEG = float('-inf')
if(math.ceil(N / 2) < K):
    print("Impossible")
    sys.exit()

prev2 = [0] + [NEG] * K   
prev1 = [0] + [NEG] * K   
for i in range(N):
    cur = prev1[:]                    
    a = A[i]
    for j in range(1, K + 1):
        v = prev2[j - 1]
        if v != NEG and v + a > cur[j]:
            cur[j] = v + a            
    prev2, prev1 = prev1, cur
print(prev1[K])