#include <iostream>
using namespace std;
constexpr int N = 3e5 + 5;
constexpr long long INF = 1e18;
int a[N];
pair<long long, int> dp[N][2];
signed main()
{
ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
// freopen("input.txt", "r", stdin);
int n, k;
cin >> n >> k;
for (int i = 0; i < n; i++) {
cin >> a[i];
}
long long low = 0, high = (long long) 1e9 * n;
auto solve = [&](const long long lambda) {
dp[0][0] = {0, 0};
dp[0][1] = {-INF, 0};
for (int i = 0; i < n; i++) {
dp[i + 1][0] = max(dp[i][0], dp[i][1]);
dp[i + 1][1] = max(dp[i][1], pair<long long, int>{dp[i][0].first - lambda, dp[i][0].second + 1});
dp[i + 1][1].first += a[i];
}
return max(dp[n][0], dp[n][1]);
};
while (low < high) {
long long mid = (low + high + 1) / 2;
if (solve(mid).second > k) {
low = mid;
} else {
high = mid - 1;
}
}
cout << solve(low).first + k * low;
return 0;
}
