import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

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

	void run() {
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		int m = sc.nextInt();
		long[][] a = new long[m][m];
		for (int i = 0; i < m; ++i) {
			for (int j = 0; j < m; ++j)
				a[i][j] = sc.nextLong();
		}
		long[][] v = new long[m][1];
		v = mul(pow(a, n - 1), v);
		long ans = 0;
		for (int i = 0; i < v.length; ++i)
			ans = Math.max(ans, v[i][0]);
		System.out.println(ans);
	}

	long[][] pow(long[][] a, long n) {
		if (a.length != a[0].length)
			throw new AssertionError();
		long[][] ret = new long[a.length][a.length];
		for (; n > 0; n >>= 1, a = mul(a, a)) {
			if (n % 2 == 1) {
				ret = mul(ret, a);
			}
		}
		return ret;
	}

	long[][] mul(long[][] a, long[][] b) {
		long[][] ret = new long[a.length][b[0].length];
		for (int i = 0; i < a.length; ++i) {
			for (int j = 0; j < b[i].length; ++j) {
				for (int m = 0; m < a[i].length; ++m) {
					ret[i][j] = Math.max(ret[i][j], a[i][m] + b[m][j]);
				}
			}
		}
		return ret;
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

}