#include <bits/stdc++.h>

using namespace std;

#define int long long
#define pb push_back
#define endl '\n'
#define VI vector<int>
#define pii pair<int, int>
#define rep(i, j, k) for (int i = j; i <= k; ++i)
#define per(i, j, k) for (int i = j; i >= k; --i)
#define print(a) cout << a << endl;

const int inf = 0x3f3f3f3f;
const long long llinf = (long long)0x3f3f3f3f3f3f3f3f;
const long long MOD = (long long)1e9 + 7LL;
const size_t N = (size_t)1e6 + 5;

#define IO                       \
    ios::sync_with_stdio(false); \
    std::cin.tie(0);             \
    std::cout.tie(0)

#define debug(a) std::cerr << "\033[34m" << #a << ':' << a << "\033[0m" << endl

#define debugList(list)                        \
    std::cerr << "\033[34m" << #list << ": ["; \
    for (auto& e : list) {                     \
        std::cerr << e << ", ";                \
    }                                          \
    std::cerr << "\b\b]\033[0m" << endl

#define otto auto

int a[1010][1010];

void solve() {
    int n;
    cin >> n;
    memset(a, inf, sizeof(a));
    int x, y;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> a[i][j];
            if (a[i][j] == -1) {
                x = i;
                y = j;
            }
        }
    }
    cout << min(a[x - 1][y], a[x + 1][y]) + min(a[x][y - 1], a[x][y + 1]);
}   

signed main() {
    IO;
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    solve();
    return 0;
}