import java.awt.Point;
import java.io.*;
import java.math.BigInteger;
import java.security.KeyStore.Builder;
import java.util.*;

import static java.lang.Math.*;

public class Testt {

    final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;
    BufferedReader in;
    PrintWriter out;
    StringTokenizer tok = new StringTokenizer("");

    void init() throws FileNotFoundException {
        if (ONLINE_JUDGE) {
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        } else {
            in = new BufferedReader(new FileReader("input.txt"));
            out = new PrintWriter("output.txt");
        }
    }

    String readString() throws IOException {
        while (!tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }

    int readInt() throws IOException {
        return Integer.parseInt(readString());
    }

    long readLong() throws IOException {
        return Long.parseLong(readString());
    }

    double readDouble() throws IOException {
        return Double.parseDouble(readString());
    }

    public static void main(String[] args) {
        new Testt().run();
    }

    public void run() {
        try {
            long t1 = System.currentTimeMillis();
            init();
            solve();
            out.close();
            long t2 = System.currentTimeMillis();
            System.err.println("Time = " + (t2 - t1));
        } catch (Exception e) {
            e.printStackTrace(System.err);
            System.exit(-1);
        }
    }

    // solve! good luck :)
    ArrayList<Integer> graph[];
    boolean [] used;
    int n;
    HashMap<String, Integer> map;
    HashMap<Integer, String> map2;
    ArrayList<Integer> ans;
    public void solve() throws IOException {

        int n = readInt();
        int[][] a = new int[n][n];
        for (int i = 0; i < n; i++) {
            for (int j = i+1; j < n; j++) {
                a[i][j] = readInt();
            }
        }
        int sum=0;
        int maxi=0;
        for (int t = 1; t < n; t++)
        {
            sum=0;
            for (int i = 0; i< t; i++)
            {
                for (int j = t; j < n; j++) sum+=a[i][j];
            }
            maxi = max(maxi,sum);
        }
    //  out.print(maxi);
        int[][] b = new int[n][n];
        for (int i = 0; i < n; i++) {
            for (int j = i+1; j < n; j++) {
                b[j][i] = readInt();
            }
        }
        int maxi2=0;
        for (int t = 1; t < n; t++)
        {
            sum=0;
            for (int i = 0; i< t; i++)
            {
                for (int j = t; j < n; j++) sum+=a[j][i];
            }
            maxi2  = max(maxi2,sum);
        }
        int ans = max(maxi,maxi2);
        if (ans % 36 != 0) {
            ans/=36;
            ans++;
        }
        else ans/=36;
        out.print(ans);
    }
}