#include <bits/stdc++.h>
using namespace std;
const int nax = 4005;
int n, m;
long long int a[nax];
vector<long long int> reku(int L, int R) {
  if (L > R) return {0};
  if (L == R) {
    return {0, a[L] * (m - 1)};
  }
  int pos = L;
  long long int v = a[L];
  for (int i = L; i <= R; i++) {
    if (a[i] < v) {
      v = a[i];
      pos = i;
    }
  }
  auto LF = reku(L, pos - 1);
  auto RG = reku(pos + 1, R);
  vector<long long int> ans(R - L + 2, -2e18);
  for (int i = 0; i < LF.size(); i++) {
    for (int j = 0; j < RG.size(); j++) {
      ans[i + j] = max(ans[i + j], LF[i] + RG[j] - v * i * j * 2);
      ans[i + j + 1] =
          max(ans[i + j + 1],
              LF[i] + RG[j] + v * m - v * i * j * 2 - v - v * (i + j) * 2);
    }
  }
  return ans;
}
void solve() {
  cin >> n >> m;
  for (int i = 1; i <= n; i++) cin >> a[i];
  auto res = reku(1, n);
  cout << res[m] << "\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int tt = 1;
  while (tt--) solve();
  return 0;
}
