#!/usr/bin/env python3
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np

# %%
N = int(readline())
M = int(readline())
A = np.array(read().split(), np.int64).reshape(M, M)

# %%


def merge(A, B):
    return (A[:, :, None] + B[None, :, :]).max(axis=1)

# %%


def power(A, n):
    if n == 1:
        return A
    B = power(A, n // 2)
    B = merge(B, B)
    if n % 2 == 0:
        return B
    return merge(A, B)


# %%
print(power(A, N - 1).max())