import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        long n = Long.parseLong(br.readLine()) - 1;
        int m = Integer.parseInt(br.readLine());
        long[][][] values = new long[34][m][m];
        for (int i = 0; i < m; i++) {
            String[] line = br.readLine().split(" ", m);
            for (int j = 0; j < m; j++) {
                values[0][i][j] = Integer.parseInt(line[j]);
            }
        }
        for (int i = 1; i < 34; i++) {
            for (int j = 0; j < m; j++) {
                for (int k = 0; k < m; k++) {
                    for (int l = 0; l < m; l++) {
                        values[i][j][k] = Math.max(values[i][j][k], values[i - 1][j][l] + values[i - 1][l][k]);
                    }
                }
            }
        }
        long[][] ans = new long[m][m];
        for (int i = 33; i >= 0 && n > 0; i--) {
            if (n < (1L << i)) {
                continue;
            }
            long[][] next = new long[m][m];
            n -= (1L << i);
            for (int j = 0; j < m; j++) {
                for (int k = 0; k < m; k++) {
                    for (int l = 0; l < m; l++) {
                        next[j][k] = Math.max(next[j][k], ans[j][l] + values[i][l][k]);
                    }
                }
            }
            ans = next;
        }
        long max = 0;
        for (long[] arr : ans) {
            for (long x : arr) {
                max = Math.max(x, max);
            }
        }
        System.out.println(max);
    }
}