#include<bits/stdc++.h>
#include<stdio.h>
#include<limits.h>
using namespace std;
#define ROW 1001
#define COL 1001
typedef unsigned long long ull;
const long long M=1e9+7;
struct cell
{
    ull x, y;
    ull distance;
    cell(ull x, ull y, ull distance) :
        x(x), y(y), distance(distance) {}
};

bool operator<(const cell& a, const cell& b)
{
    if (a.distance == b.distance)
    {
        if (a.x != b.x)
            return (a.x < b.x);
        else
            return (a.y < b.y);
    }
    return (a.distance < b.distance);
}



ull shortest(ull grid[ROW][COL], ull row, ull col)
{
    ull dis[row][col];
    for (ull i = 0; i < row; i++)
        for (ull j = 0; j < col; j++)
            dis[i][j] = INT_MAX;
    int  dx[] = {-1, 0, 1, 0};
    int  dy[] = {0, 1, 0, -1};

    set<cell> st;
    st.insert(cell(0, 0, 0));
    dis[0][0] = grid[0][0];
    while (!st.empty())
    {
        cell k = *st.begin();
        st.erase(st.begin());
        for (ull i = 0; i < 4; i++)
        {
            ull x = k.x + dx[i];
            ull y = k.y + dy[i];
            if (!(x>=0 && x<=row-1 &&y>=0 && y<=col-1))
                continue;
            if (dis[x][y] > dis[k.x][k.y] + grid[x][y])
            {
                if (dis[x][y] != INT_MAX)
                    st.erase(st.find(cell(x, y, dis[x][y])));
                dis[x][y] = dis[k.x][k.y] + grid[x][y];
                st.insert(cell(x, y, dis[x][y]));
            }
        }
    }

    return dis[row - 1][col - 1];
}

int  main()
{
    ull n;
    cin >>n;
    ull cost[ROW][COL];
    for(ull i=0;i<n;i++)
    {
        for(ull j=0;j<n;j++)
        {
            cin >>cost[i][j];
        }
    }
    ull  ans=shortest(cost, n, n);
    cout<<ans;

return 0;
}