#include <bits/stdc++.h>
using namespace std;
#define int int64_t
pair<int, int> f(int penalty, vector<int> &a) {
vector<array<int, 2>> dp(a.size()), cnt(a.size());
dp[0][0] = 0, cnt[0][0] = 0;
dp[0][1] = a[0] - penalty;
cnt[0][1] = 1;
for (int i = 1; i < a.size(); i++) {
dp[i][0] = max(pair<int, int>{dp[i - 1][0], cnt[i - 1][0]},
pair<int, int>{dp[i - 1][1], cnt[i - 1][1]})
.first;
cnt[i][0] = max(pair<int, int>{dp[i - 1][0], cnt[i - 1][0]},
pair<int, int>{dp[i - 1][1], cnt[i - 1][1]})
.second;
dp[i][1] = max(pair<int, int>{dp[i - 1][0] - penalty + a[i], cnt[i - 1][0] + 1},
pair<int, int>{dp[i - 1][1] + a[i], cnt[i - 1][1]})
.first;
cnt[i][1] = max(pair<int, int>{dp[i - 1][0] - penalty + a[i], cnt[i - 1][0] + 1},
pair<int, int>{dp[i - 1][1] + a[i], cnt[i - 1][1]})
.second;
}
return max(pair<int, int>{dp.back()[0], cnt.back()[0]},
pair<int, int>{dp.back()[1], cnt.back()[1]});
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
int n, k;
cin >> n >> k;
vector<int> a(n);
for (auto &x : a)
cin >> x;
int l = 0, r = 1e15;
while (l < r) {
int mid = (l + r + 1) >> 1;
f(mid, a).second >= k ? l = mid : r = mid - 1;
}
cout << f(l, a).first + l * k << '\n';
}
