#include<iostream>
#include<string>
#include<queue>
#include<vector>
#include<cassert>
#include<random>
#include<set>
#include<map>
#include<cassert>
#include<unordered_map>
#include<bitset>
#include<numeric>
#include<algorithm>
using namespace std;
typedef long long ll;
const int inf=1<<30;
const ll INF=1LL<<62;
typedef pair<int,ll> P;
typedef pair<int,P> PP; 
const ll MOD=998244353;


int main(){
    int N;
    cin>>N;
    vector<vector<int>> F(N,vector<int>(N));
    for(int i=0;i<N;i++){
        for(int j=0;j<N;j++){
            cin>>F[i][j];
        }
    }
    //unordered_map<int,int> ump;
    vector<int> ump(1<<N);
    for(int S=0;S<(1<<N);S++){
        ump[S]=-1;
        for(int i=0;i<N;i++){
            if((S>>i)&1) continue;
            ump[S]=i;
            break;
        }
    }
    /*
    vector<int> dp(1<<N,-inf);
    dp[0]=0;
    for(int S=0;S<(1<<N);S++){
        int idx=ump[S];
        if(idx==-1) continue;
        for(int j=idx+1;j<N;j++){
            if(S>>j&1) continue;
            dp[S|(1<<idx)|(1<<j)]=max(dp[S|(1<<idx)|(1<<j)],dp[S]+F[idx][j]);
        }
    }
    */
    map<int,int> dp;
    dp[0]=0;
    for(auto [S,v]:dp){
        int idx=ump[S];
        if(idx==-1) continue;
        for(int j=idx+1;j<N;j++){
            if((S>>j)&1) continue;
            dp[S|(1<<idx)|(1<<j)]=max(dp[S|(1<<idx)|(1<<j)],dp[S]+F[idx][j]);
        }
    }
    int all=(1<<N)-1;
    cout<<dp[all]<<endl;
}