#include <bits/stdc++.h>
using namespace std;
 
#define REP(i,n) for (int i=0,_n=(int)(n); i < _n; i++)
template<class T> bool chkmin(T &a, T b) { return a > b ? (a = b, true) : false; }
template<class T> bool chkmax(T &a, T b) { return a < b ? (a = b, true) : false; }

typedef long long ll;

int dp[1 << 24];
int F[24][24];

int main2() {
  memset(dp, 0, sizeof(dp));
  int N; cin >> N;
  REP(i, N) REP(j, N) cin >> F[i][j];

  REP(set, 1 << N) {
    if(__builtin_popcount(set) % 2 == 1) continue;
    int a = 0;
    REP(i, N) if ((set >> i & 1) == 0) {
      a = i;
      break;
    }
    for (int j = a + 1; j < N; j++) if ((set >> j & 1) == 0) {
      chkmax(dp[set | (1 << a) | (1 << j)], dp[set] + F[a][j]);
    }
  }

  cout << dp[ (1 << N) - 1 ] << endl;

  return 0;
}

int main() {
  for (;!cin.eof();cin>>ws) main2();
  return 0;
}