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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        long n = sc.nextLong() - 1;
        int m = sc.nextInt();
        long[][][] dp = new long[33][m][m];
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < m; j++) {
                dp[0][i][j] = sc.nextInt();
            }
        }
        for (int i = 1; i < 33; i++) {
            for (int j = 0; j < m; j++) {
                for (int k = 0; k < m; k++) {
                    for (int l = 0; l < m; l++) {
                        dp[i][j][k] = Math.max(dp[i][j][k], dp[i - 1][j][l] + dp[i - 1][l][k]);
                    }
                }
            }
        }
        long[][] current = new long[m][m];
        for (int i = 32; i >= 0; i--) {
            if (n < (1L << i))  {
                continue;
            }
            n -= (1L << i);
            long[][] next = new long[m][m];
            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], current[j][l] + dp[i][l][k]);
                    }
                }
            }
            current = next;
        }
        long max = 0;
        for (long[] arr : current) {
            for (long x : arr) {
                max = Math.max(max, x);
            }
        }
        System.out.println(max);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String nextLine() throws Exception {
        return br.readLine();
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}