#include "fstream"
using namespace std;
ifstream cin("input.txt");
ofstream cout("output.txt");
int a[31][31];
int main()
{
        int m, n, k, max, t, result;
        cin >> k >> n >> m;

        for (int i = 1; i <= n; i++)
        {
                for (int j = 1; j <= m; j++)
                {
                        cin >> a[i][j];
                }
        }
        int h = 3;
        max = a[n][1];
        for (int j = 1; j < m; j++)
        {
                if (max < a[h][j])
                {
                        max = a[h][j];
                        t = j;
                }
                else t = 1;
        }
        result = max;
        k--;
        for (int i = n; i >= 0; i++)
        {
                if (a[i][t + 1] >= a[i - 1][t] && a[i][t + 1] >= a[i][t - 1] && k>0)
                {
                        result = result + a[i][t+1];
                        t++;
                        k--;
                        i--;
                }
                else if (a[i - 1][t] >= a[i][t + 1] && k>0)
                {
                        result = result + a[i - 1][t];
                        k--;
                }
                else break;
        }
        cout << result << endl;
        system("pause");
        return 0;
}