#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define all(v) v.begin(), v.end()
using namespace std;
using pii = pair<int, int>;
constexpr int inf = 1e18;
int n, k;
vector<int> a;
pii f(int lambda) {
vector<vector<pii>> dp(n + 1, vector<pii>(2, {-inf, -inf})); // sum, nos
dp[0][0] = {0, 0};
for (int i = 1; i <= n; ++i) {
dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
dp[i][1] = max(
make_pair(dp[i - 1][0].fi + a[i] - lambda, dp[i - 1][0].se + 1),
make_pair(dp[i - 1][1].fi + a[i], dp[i - 1][1].se)
);
}
return max(dp[n][0], dp[n][1]);
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> k;
a.resize(n + 1);
for (int i = 1; i <= n; ++i) cin >> a[i];
int l = 0, r = 1e14, bres = -1;
while (l <= r) {
int mid = (l + r) / 2;
pii res = f(mid);
if (res.se <= k) {
bres = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
pii res = f(bres);
cout << res.fi + bres * k << '\n';
}
