#include <stdio.h>
#include <iostream>
#include <vector>
#define rep(i,s,t) for (register int i = (s), i##_ = (t) + 1; i < i##_; ++ i)
#define pre(i,s,t) for (register int i = (s), i##_ = (t) - 1; i > i##_; -- i)
const int N = 505;
using ll = long long;
int n, m, s, t, t1, t2, t3, t4, tme;

int head[N], mlc = 1;
struct ep {
    int to, next;
  ll flow, cost;
} e[N * N * 2];
static inline void adde(int u, int v, ll fl, int cs, bool __same = false) {
    e[++ mlc] = { v, head[u], fl, cs };
    head[u] = mlc;
    e[++ mlc] = { u, head[v], (__same ? fl : 0), -cs };
    head[v] = mlc;
}

int vis[N], fa[N], fae[N];
void dfs(int u) {
  vis[u] = 1;
  for (int i = head[u], v; i; i = e[i].next) {
    if (!vis[v = e[i].to] and e[i].flow) 
      fa[v] = u, fae[v] = i, dfs(v);
  }
}

int pi[N];
int phi(int x) { 
  if (vis[x] == tme) return pi[x];
  return vis[x] = tme, pi[x] = phi(fa[x]) - e[fae[x]].cost;
}

int cyc[N];
ll cost;
#define swap(x, y) { int t = x; x = y; y = t; }
static inline void pushflow(int id) {
  int pen = e[id ^ 1].to, lca = e[id].to;
  ++ tme;
  while (pen) vis[pen] = tme, pen = fa[pen];
  while (vis[lca] != tme) vis[lca] = tme, lca = fa[lca];
  int e2 = 0, f = e[id].flow, path = 2, clen = 0;
  for (int i = e[id ^ 1].to; i != lca; i = fa[i]) {
    cyc[++ clen] = fae[i];
    if (e[fae[i]].flow < f) f = e[fae[e2 = i] ^ (path = 0)].flow;
  }
  for (int i = e[id].to; i != lca; i = fa[i]) {
    cyc[++ clen] = fae[i] ^ 1;
    if (e[fae[i] ^ 1].flow < f) f = e[fae[e2 = i] ^ (path = 1)].flow;
  }
  cyc[++ clen] = id;

  rep(i,1,clen) {
    e[cyc[i]].flow -= f, e[cyc[i] ^ 1].flow += f;
    cost += 1ll * f * e[cyc[i]].cost;
  }
  if (path == 2) return;

  int lste = id ^ path, lst = e[lste].to, now = e[lste ^ 1].to;
  while (lst != e2) {
    vis[now] --;
    lste ^= 1;
    swap(lste, fae[now]);
    swap(lst, fa[now]);
    swap(lst, now);
  }
}

static inline ll simplex(int s, int t) {
  int lhead = head[s], rhead = head[t];
  adde(t, s, 1e13, -0x3f3f3f3);
  dfs(t);
  vis[t] = tme = 2, fa[t] = cost = 0;
  for (int i = 2, pre = mlc; i != pre; i = (i == mlc ? 2 : i + 1)) {
    if (e[i].flow and e[i].cost < phi(e[i ^ 1].to) - phi(e[i].to)) 
      pushflow(pre = i);
  } 
  head[s] = lhead, head[t] = rhead;
  mlc -= 2;
  return e[mlc + 2].flow;
}

using namespace std;

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  int N = (n + 1) / 2;
  int S = N * 2, T = N * 2 + 1;
  s = S, t = T;
  std::vector<vector<int>> a(n, vector<int>(n, 0));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      cin >> a[i][j];
    }
  }
  for (int i = 0; i < n; i += 2) {
    adde(S, i / 2, 1, 0);
    adde(i / 2 + N, T, 1, 0);
  }
  for (int i = 0; i < n; i += 2) {
    for (int j = 0; j < n; j += 2) {
      int l = j - 1;
      int r = j + 1;
      int v = 0;
      if (l >= 0) {
        v += a[i][l];
      }
      if (r < n) {
        v += a[i][r];
      }
      adde(i / 2, j / 2 + N, 1, v);
    }
  }
  ll flow = simplex(s, t);
  cout << cost + 1ll * flow * 0x3f3f3f3 << "\n";
}