#include <bits/stdc++.h>
using namespace std;

using i64 = long long;

void solve()
{
    int N;
    cin >> N;
    vector<vector<int>>  dp(N + 1, vector<int>(N + 1, 1e9));
    for (int i = 1; i <= N; i++)
    {
        for (int j = 1; j <= N; j++)
        {
            cin >> dp[i][j];
        }
    }
    for (int i = 1; i <= N; i++)
    {
        for (int j = 1; j <= N; j++)
        {
            if (i == 1 && j == 1)
            {
                continue;
            }
            dp[i][j] += min(dp[i - 1][j], dp[i][j - 1]);
        }
    }
    cout << dp[N][N] << '\n';
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int _ = 1;

    // cin >> _;
    while (_--)
    {
        solve();
    }
    return 0;
}