O(n ^ 3)
#include<bits/stdc++.h>
using namespace std;
const int N = 310;
int w[N][N];
int a[N];
int f[N][N];
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int n;
    cin >> n;

    for(int i = 1;i <= n;i++)
    {
        cin >> a[i];
        a[i] += a[i - 1];
    }

    for(int i = 1;i <= n;i++)
    {
        for(int j = 1;j <= n;j++)
        {
            w[i][j] = a[j] - a[i - 1];
        }
    }

    memset(f, 0x3f, sizeof f);
    for(int i = 1;i <= n;i++)f[i][i] = 0;

    for(int len = 2;len <= n;len++)
    {
        for(int i = 1;i <= n - len + 1;i++)
        {
            int j = i + len - 1;
            for(int k = i;k <= j;k++)
            {
                f[i][j] = min(f[i][j], f[i][k] + f[k + 1][j] + w[i][j]);
            }
        }
    }

    cout << f[1][n] << endl;
    return 0;
}