void main(){
  import std.stdio, std.string, std.conv, std.algorithm;

  int n; rd(n);
  auto a=new int[][](n, n);
  foreach(i; 0..n) a[i]=readln.split.to!(int[]);

  auto rec=new int[](1<<n);
  fill(rec, -1);
  int fun(int bit){
    if(bit==0) return 0;
    if(rec[bit]>=0) return rec[bit];
    int ret=0;
    foreach(i; 0..n)if(bit&(1<<i)){
      foreach(j; (i+1)..n)if(bit&(1<<j)){
        ret=max(ret, fun(bit^(1<<i)^(1<<j))+a[i][j]);
      }
      break;
    }
    return rec[bit]=ret;
  }

  writeln(fun((1<<n)-1));
}

void rd(T...)(ref T x){
  import std.stdio, std.string, std.conv;
  auto l=readln.split;
  assert(l.length==x.length);
  foreach(i, ref e; x){
    e=l[i].to!(typeof(e));
  }
}