import itertools
import sys
input = sys.stdin.readline
H, W = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(H)]
dir = [-1, 0, 1]
pos = []
for i in range(H+2):
    if i==0 or i==H+1:
        for j in range(W+2):
            pos.append((i, j))
    else:
        pos.append((i, 0))
        pos.append((i, W+1))
ans = 0
for x, y in pos:
    for dx, dy in itertools.product(dir, repeat=2):
        if dx==dy==0:
            continue
        for x2, y2 in pos:
            for dx2, dy2 in itertools.product(dir, repeat=2):
                if dx2==dy2==0:
                    continue
                S = set()
                nx = x
                ny = y
                nx+=dx
                ny+=dy
                while 1<=nx<=H and 1<=ny<=W:
                    S.add((nx, ny))
                    nx+=dx
                    ny+=dy
                nx2 = x2
                ny2 = y2
                nx2+=dx2
                ny2+=dy2
                while 1<=nx2<=H and 1<=ny2<=W:
                    S.add((nx2, ny2))
                    nx2+=dx2
                    ny2+=dy2

                sco=0
                for i, j in S:
                    sco += A[i-1][j-1]
                
                ans = max(ans, sco)
print(ans)