#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pii pair<int,int>
#define inp(name) freopen(name, "r", stdin);
#define out(name) freopen(name, "w", stdout);
const int N = 3e3 + 5;
int n, k;
int a[N];
int dp[N][N], prefix[N];
int calc(int i, int j){
if (i > j) return 0;
return (prefix[j] - prefix[i - 1]) * (prefix[j] - prefix[i - 1]);
}
void solve(int l, int r, int pos, int lf, int rt){
if (l > r) return;
int mid = (l + r)/2;
pair <int, int> min_dp = {1e18, 0};
for (int i = lf; i <= min(mid, rt); i ++){
if (dp[pos - 1][i] + calc(i + 1, mid) < min_dp.fi) min_dp = {dp[pos - 1][i] + calc(i + 1, mid), i};
}
dp[pos][mid] = min_dp.fi;
solve(l, mid - 1, pos, lf, min_dp.se);
solve(mid + 1, r, pos, min_dp.se, rt);
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n >> k;
int sum = 0;
for (int i = 1; i <= n; i ++){
cin >> a[i];
prefix[i] = prefix[i - 1] + a[i];
}
for (int i = 1; i <= n; i ++) dp[0][i] = calc(0, i);
for (int i = 1; i <= k; i ++){
solve(1, n, i, 1, n);
}
cout << (prefix[n] * prefix[n] - dp[k][n])/2;
}
