#include <stdio.h>
#define Lg 110

using namespace std;

int cap[Lg][Lg],cost[Lg][Lg];
int n,m,S,D,rez,inc,sf,Cost_aux;
int Q[Lg*Lg],tati[Lg],Cost[Lg];
char viz[Lg];

void citire()
{
     freopen ("cc.in","r",stdin);
     freopen ("cc.out","w",stdout);
     scanf ("%d",&n);
     S=0;
     D=2*n+1;
     for (int i=1;i<=n;i++)
     {
          cap[S][i]=1;
          for (int j=n+1;j<=n+n;j++)
           {
               scanf ("%d",&cost[i][j]);
               cost[j][i]=-cost[i][j];
               cap[j][D]=1;
               cap[i][j]=1;
          }
     }
}

void bell_BMW()
{
     int N,N1,in,ssf;
     for (int  i=0;i<=2*n+1;i++)
          Cost[i]=6000000LL;
     inc=0;
     sf=1;
     Q[inc]=S;
     Cost[S]=0;
     viz[S]=1;
     while (inc<sf)
     {
           N=Q[inc++];
          viz[N]=0;
          Cost_aux=Cost[N];
          int in=n+1,ssf=2*n+1;
          if (N==S)
          {
               in=1;
               ssf=n;
          }
          for (N1=in;N1<=ssf;N1++)
          {
               if (cap[N][N1] && Cost[N1]>=Cost_aux+cost[N][N1])
               {
                    Cost[N1]=Cost_aux+cost[N][N1];
                    tati[N1]=N;
                    if (!viz[N1])
                    {
                         viz[N1]=1;
                         Q[sf++]=N1;
                    }
               }
          }
     }
}

void fmcm()
{
     int flux,poz,T;
     bell_BMW();
     while (Cost[D]!=6000000LL)
     {
          flux=6000000LL;
          poz=D;
          while (poz!=S)
          {
               T=tati[poz];
               flux=(flux>cap[T][poz])?cap[T][poz]:flux;
               poz=T;
          }

          poz=D;
          while (poz!=S)
          {
               T=tati[poz];
               cap[T][poz]-=flux;
               cap[poz][T]+=flux;
               poz=T;
          }
          rez+=Cost[D];
          bell_BMW();
     }
}

int main ()
{
     citire();
     fmcm();
     printf("%d\n",rez);
     return 0;
}