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 in range(H+W+1):
    if 0<=x<=H+1:
        dir = [(0, 1), (1, 1), (-1, 1)]
    else:
        dir = [(1, 0), (1, 1), (1, -1)]
    for dx, dy in dir:
        for x2 in range(x+1, H+W+1):
            if 0<=x2<=H+1:
                dir2 = [(0, 1), (1, 1), (-1, 1)]
            else:
                dir2 = [(1, 0), (1, 1), (1, -1)]
            for dx2, dy2 in dir2:
                S = set()
                if 0<=x<=H+1:
                    nx = x
                    ny = 0
                else:
                    nx = 0
                    ny = x-(H)
                nx+=dx
                ny+=dy
                while 1<=nx<=H and 1<=ny<=W:
                    S.add((nx, ny))
                    nx+=dx
                    ny+=dy

                if 0<=x2<=H+1:
                    nx2 = x2
                    ny2 = 0
                else:
                    nx2 = 0
                    ny2 = x2-(H)
                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)