#include <bits/stdc++.h>

using namespace std;

void input(string f)
{
	string one = f + ".in";
	string two = f + ".out";

	freopen(one.c_str(), "r", stdin);
	freopen(two.c_str(), "w", stdout);	
}

const int N = 1e5 + 7;
const int K = 1e2 + 7;
const int inf = 1e9;

int a[N], n;
int dp[N][K];

int solve(int pos, int left){
	if(pos > n){
		return 0;
	}
	if(left < 0){
		return -inf;
	}

	return dp[pos][left];
}

int solve2(int pos, int left){
	if(a[pos] == 0){
		return solve(pos + 1, left - 1) + a[pos];
	}

	return solve(pos + 1, left) + a[pos];
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);

	input("krasi");

	int k;

	cin >> n >> k;

	for(int i = 1; i <= n; i++){
		cin >> a[i];
	}

	for(int pos = n; pos >= 1; pos--){
		for(int left = 0; left <= k; left++){
			if(a[pos] == 0){
				dp[pos][left] = max(0, solve(pos + 1, left - 1) + a[pos]);
			}
			else{
				dp[pos][left] = max(0, solve(pos + 1, left) + a[pos]);
			}
		}
	}

	int res = solve2(1, k);

	for(int i = 2; i <= n; i++){
		res = max(res, solve2(i, k));
	}

	cout << res << "\n";

	return 0;
}