#include <bits/stdc++.h>
#define pii pair<int, int>
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define ll long long
#define ld long double
#define sz(v) int(v.size())
#define all(v) v.begin(), v.end()
using namespace std;
const int N = (int) 1000;
const int M = (int) 2e6 + 10;
const ll LINF = (ll) 1e18;
const int INF = (int) 1e9 + 7;
const double EPS = (double) 1e-9;
int n, k;
ll dp[2][N][N];
int a[N];
int sum(int l, int r) {
return a[r] - a[l - 1];
}
int main() {
#define fn "balls"
#ifdef witch
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#else
// freopen(fn".in", "r", stdin);
// freopen(fn".out", "w", stdout);
#endif
cin >> n >> k;
for (int i = 1; i <= n; i++) {
cin >> a[i];
a[i] += a[i - 1];
}
for (int i = 1; i <= k; i++) {
for (int l = 1; l <= n; l++) {
for (int r = l; r <= n; r++) {
ll &ans = dp[i % 2][l][r];
ans = 0;
for (int d = l; d < r; d++) {
ans = max(ans, sum(l, d) * 1ll * sum(d + 1, r) + max(dp[1 - i % 2][l][d], dp[1 - i % 2][d + 1][r]));
}
}
}
}
cout << dp[k % 2][1][n] << endl;
return 0;
}
