D

#include <bits/stdc++.h>
using namespace std;

#define ll     long long

int main()
{
    int n;
    cin>>n;

    vector<vector<ll int>> edge(n, vector<ll int> (n));
    int tmp;

    for(int i=0; i<n-1; i++)
    {
        for(int j=i+1; j<n; j++)
        {
            cin>>tmp;
            edge[i][j] = edge[j][i] = tmp;
        }
    }

    vector<ll int> dp ((1<<n), -1);

    function<ll int(int)> solve = [&](int mask)
    {
        if(mask+1 == (1<<n))      return 0ll;
        if(dp[mask] != -1)        return dp[mask];

        int i = -1;
        for(int b=0; b<n; b++)
        {
            if(((1<<b)&mask) == 0)
            {
                i = b;
                break;
            }
        }

        if(i == -1)               return 0ll;

        dp[mask] = max(0ll, solve(mask|(1<<i)));

        for(int j=0; j<n; j++)
        {
            if(j==i || (mask&(1<<j))>0)     continue;
            dp[mask] = max(dp[mask], edge[i][j] + solve(mask|(1<<j)|(1<<i)));
        }

        return dp[mask];
    };

    cout<<solve(0)<<"\n";
}