#include <bits/stdc++.h>

using namespace std;
const int N = 110;

int n;
int w[N][N], f[N][N];

int main() {
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            cin >> w[i][j];

    // 初始化为最大值
    memset(f, 0x3f, sizeof f);

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++) {
            if (i == 1 && j == 1)
                f[i][j] = w[i][j]; // 特事特办，不用追求完美的一体化表现，合理特判，逻辑简单
            else
                f[i][j] = min(f[i - 1][j], f[i][j - 1]) + w[i][j];
        }

    printf("%d\n", f[n][n]);
    return 0;
}