INF=10**18
 
def solve():
 
    n,k=map(int,input().split())
    a=[0]+list(map(int,input().split()))
 
    dp=[[-INF]*(k+1)for _ in range(n+1)]
    dp[0][0]=0
 
    if n>=1:
        dp[1][0]=0
        if k>=1:dp[1][1]=a[1]
    if n>=2:
        dp[2][0]=0
        if k>=1:dp[2][1]=max(a[1],a[2])
    for i in range(3,n+1):
        dp[i][0]=0
        for j in range(1,k+1):
            dp[i][j]=max(a[i]+dp[i-2][j-1],dp[i-1][j])
 
    print(dp[n][k])
solve()

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NSAyCjMgMiA3IDEwIDEy

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