#include <bits/stdc++.h>
using namespace std;
const int N = 4005;
const long long INF = 0x3f3f3f3f3f3f3f3f;
template <typename T>
inline void read(T &WOW) {
  T x = 0, flag = 1;
  char ch = getchar();
  while (!isdigit(ch)) {
    if (ch == '-') flag = -1;
    ch = getchar();
  }
  while (isdigit(ch)) {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  WOW = flag * x;
}
template <typename T>
inline void cmax(T &x, T y) {
  if (x < y) x = y;
}
int n, m, siz[N];
long long a[N], dp[N][N];
int DP(int l, int r) {
  if (l > r) return 0;
  if (l == r) {
    siz[l] = 1;
    dp[l][0] = 0;
    dp[l][1] = a[l] * (m - 1);
    return l;
  }
  int u = l;
  for (int i = l + 1; i <= r; ++i) {
    if (a[i] < a[u]) u = i;
  }
  int v1 = DP(l, u - 1), v2 = DP(u + 1, r);
  siz[u] = min(m, r - l + 1);
  for (int i = 0; i <= siz[u]; ++i) {
    dp[u][i] = -INF;
  }
  for (int i = 0; i <= siz[v1]; ++i) {
    for (int j = 0; j <= siz[v2] && i + j <= siz[u]; ++j) {
      cmax(dp[u][i + j], dp[v1][i] + dp[v2][j] - a[u] * 2 * i * j);
      if (i + j + 1 <= siz[u]) {
        cmax(dp[u][i + j + 1],
             dp[v1][i] + dp[v2][j] - a[u] * (2 * (i * j + i + j) - (m - 1)));
      }
    }
  }
  return u;
}
void solve() {
  read(n);
  read(m);
  for (int i = 1; i <= n; ++i) {
    read(a[i]);
  }
  int rt = DP(1, n);
  printf("%lld\n", dp[rt][m]);
}
int main() {
  solve();
  return 0;
}
