import numpy as np
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

def inmax(aa,bb):
    h=len(aa)
    w=len(bb[0])
    res=np.zeros((h,w),dtype="i8")
    for i in range(h):
        for j in range(w):
            res[i][j]=np.max(aa[i]+bb[:,j])
    return res

def main():
    n=II()-1
    m=II()

    base=np.array(LLI(m),dtype="i8")
    aa=np.zeros((m,m),dtype="i8")
    while n:
        if n&1:aa=inmax(aa,base)
        base=inmax(base,base)
        n>>=1

    print(np.max(aa))

main()