#include <stdio.h>

 #include <algorithm>

 #include <string.h>

 #include <iostream>

 using namespace std;

 /*  KM算法

  *   复杂度O(nx*nx*ny)

  *  求最大权匹配

  *   若求最小权匹配，可将权值取相反数，结果取相反数

  *  点的编号从0开始

  */

 const int N = ;

 const int INF = 0x3f3f3f3f;

 int nx,ny;//两边的点数

 int g[N][N];//二分图描述

 int linker[N],lx[N],ly[N];//y中各点匹配状态，x,y中的点标号

 int slack[N];

 bool visx[N],visy[N];

 bool DFS(int x)

 {

     visx[x] = true;

     for(int y = ; y < ny; y++)

     {

         if(visy[y])continue;

         int tmp = lx[x] + ly[y] - g[x][y];

         if(tmp == )

         {

             visy[y] = true;

             if(linker[y] == - || DFS(linker[y]))

             {

                 linker[y] = x;

                 return true;

             }

         }

         else if(slack[y] > tmp)

             slack[y] = tmp;

     }

     return false;

 }

 int KM()

 {

     memset(linker,-,sizeof(linker));

     memset(ly,,sizeof(ly));

     for(int i = ;i < nx;i++)

     {

         lx[i] = -INF;

         for(int j = ;j < ny;j++)

             if(g[i][j] > lx[i])

                 lx[i] = g[i][j];

     }

     for(int x = ;x < nx;x++)

     {

         for(int i = ;i < ny;i++)

             slack[i] = INF;

         while(true)

         {

             memset(visx,false,sizeof(visx));

             memset(visy,false,sizeof(visy));

             if(DFS(x))break;

             int d = INF;

             for(int i = ;i < ny;i++)

                 if(!visy[i] && d > slack[i])

                     d = slack[i];

             for(int i = ;i < nx;i++)

                 if(visx[i])

                     lx[i] -= d;

             for(int i = ;i < ny;i++)

             {

                 if(visy[i])ly[i] += d;

                 else slack[i] -= d;

             }

         }

     }

     int res = ;

     for(int i = ;i < ny;i++)

         if(linker[i] != -)

             res += g[linker[i]][i];

     return res;

 }

 //HDU 2255

 int main()

 {

     int n;

     while(scanf("%d",&n) == )

     {

         for(int i = ;i < n;i++)

             for(int j = ;j < n;j++)

                 scanf("%d",&g[i][j]);

         nx = ny = n;

         printf("%d\n",KM());

     }

     return ;

 }