from collections import deque

N = int(input())
M = int(input())

S = []
for i in range(M):
    scores = list(map(int, input().split(' ')))
    que = deque()
    for score_index in sorted([(score,i) for i,score in enumerate(scores)]):
        que.append(score_index)
    S.append(que)

U = []
for i in range(M):
    U.append(deque())

def total(start, number):
    visited = [False for _ in range(M)]
    total = 0
    n = 0
    i = start
    
    while n < number:
        score,next = S[i].pop()
        if visited[next]:
            U[i].append((score,next))            
            continue
        visited[next] = True
        U[i].append((score,next))
        total = total + score
        i = next
        n = n + 1
        
    for j in range(M):
        for _ in range(len(U[j])):
            S[j].append(U[j].pop())
            
    return total,i

if N < M:
    print(0)
    exit(0)

division = N // M
residual = N % M

answer = 0
for i in range(M):
    total1,start = total(i,M)
    total2,last = total(start,residual-1)
    answer = max(answer, total1 * division + total2)

print(answer)