// Starcraft 2 enjoyer //
#include <bits/stdc++.h>
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
using namespace std;
#define LSOne(X) ((X) & -(X))
const int N = 3e5 + 5;
const int M = 2e5 + 5;
const int LG = 20;
const int INF = 1e9 + 5;
const int K = 2;
const int C = 26;
const int B = 1000;
const int MOD = 998244353;
long long n, k, a[N], pos[N], parent[N], sz[N], val[N], type[N], sum;
vector<pair<int, int>> v;
long long ans, cur;
set<pair<int, int>> ms1, ms2;
void del(int val, int id)
{
// cout << val << " " << id << "del\n";
auto it = ms1.find({val, id});
if (it != ms1.end())
{
sum -= val;
ms1.erase(it);
if (!ms2.empty())
{
if (prev(ms2.end())->first >= 0)
{
ms1.insert(*prev(ms2.end()));
sum += prev(ms2.end())->first;
ms2.erase(prev(ms2.end()));
}
}
}
else
{
ms2.erase(ms2.find({val, id}));
}
}
void add(int val, int id)
{
// cout << val << " " << id << "add\n";
if (ms1.empty())
{
if (val > 0)
{
ms1.insert({val, id});
sum += val;
}
else
{
ms2.insert({val, id});
}
}
else
{
if (ms1.size() < k)
{
if (val > 0)
{
ms1.insert({val, id});
sum += val;
}
else
{
ms2.insert({val, id});
}
}
else
{
if (ms1.begin()->first < val)
{
sum -= ms1.begin()->first;
ms2.insert(*ms1.begin());
ms1.erase(*ms1.begin());
ms1.insert({val, id});
sum += val;
}
else
{
ms2.insert({val, id});
}
}
}
}
int getParent(int x)
{
return parent[x] == x ? x : parent[x] = getParent(parent[x]);
}
void update(int a, int b)
{
a = getParent(a);
b = getParent(b);
if (a != b)
{
del(val[a], a);
del(val[b], b);
if (sz[a] < sz[b])
{
swap(a, b);
}
parent[b] = a;
sz[a] += sz[b];
val[a] += val[b];
add(val[a], a);
}
}
bool chkConnect(int a, int b)
{
return getParent(a) == getParent(b);
}
inline void solve()
{
cin >> n >> k;
ans = 0;
cur = 0;
for (int x = 1; x <= n; x++)
{
cin >> a[x];
v.push_back({a[x], x});
parent[x] = x;
sz[x] = 1;
val[x] = 0;
}
sort(v.rbegin(), v.rend());
for (int x = 0; x < n; x++)
{
pos[v[x].second] = x;
}
for (auto &[w, id] : v)
{
val[id] = w;
add(w, id);
if (id > 1)
{
if (pos[id - 1] < pos[id])
{
update(id - 1, id);
}
}
if (id < n)
{
if (pos[id + 1] < pos[id])
{
update(id + 1, id);
}
}
// cout << sum << " " << w << " " << id << "\n";
ans = max(ans, sum);
}
cout << ans << "\n";
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
for (int x = 1; x <= t; x++)
{
solve();
}
return 0;
}
