import sys
sys.setrecursionlimit(10000)

def rec(i, j, k):

    if memo[i][j][k]!=-1:
        return memo[i][j][k]
        
    if i==0:
        memo[i][j][k] = A[j][k]
        return A[j][k]
    
    res = 0
    
    for l in range(m):
        if res<A[j][k]+rec(i-1, k, l):
            res = A[j][k]+rec(i-1, k, l)
            to[V-i][j][k] = (k, l)
            
    memo[i][j][k] = res
    
    return res

n = int(input())
n -= 1
m = int(input())
A = [list(map(int, input().split())) for _ in range(m)]
V = m+100
memo = [[[-1]*m for _ in range(m)] for _ in range(V+1)]
to = [[[0]*m for _ in range(m)] for _ in range(V)]

for i in range(m):
    for j in range(m):
        rec(V, i, j)

ans = 0

for i in range(m):
    for j in range(m):
        flag = [[-1]*m for _ in range(m)]
        cur_i, cur_j = i, j
        cnt = 0
        flag[cur_i][cur_j] = cnt
        scores = [A[cur_i][cur_j]]
        
        while True:
            cur_i, cur_j = to[cnt][cur_i][cur_j]
            #print(cur_i, cur_j)
            if flag[cur_i][cur_j]>=0:
                #print(scores)
                ini = flag[cur_i][cur_j]
                loop = cnt+1-flag[cur_i][cur_j]
                #print(ini, loop)
                s1 = sum(scores[:ini])
                s2 = sum(scores[ini:])
                ans = max(ans, s1+(n-ini)//loop*s2+sum(scores[ini:ini+(n-ini)%loop]))
                break
            
            cnt += 1
            flag[cur_i][cur_j] = cnt
            scores.append(A[cur_i][cur_j])
    
print(ans)