import sys

# sys.setrecursionlimit(200005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = -1-(-1 << 31)
# inf = -1-(-1 << 63)
# md = 10**9+7
md = 998244353

memo = {}
ijs = {}
def line(si, sj, di, dj):
    if (si, sj, di, dj) in memo: return memo[si, sj, di, dj]
    res = 0
    i, j = si, sj
    st = set()
    while 0 <= i < h and 0 <= j < w:
        st.add((i, j))
        res += aa[i][j]
        i, j = i+di, j+dj
    memo[si, sj, di, dj] = res
    ijs[si, sj, di, dj] = st
    return res

def cross(i, j, di, dj, p, q, dp, dq):
    s=ijs[i, j, di, dj]
    t=ijs[p, q, dp, dq]
    if len(s)>len(t):s,t=t,s
    for a in s:
        if a in t:return a
    return -1,-1

def start():
    for i in range(h):
        yield i, 0, 0, 1
        yield i, 0, -1, 1
        yield i, 0, 1, 1
    for j in range(w):
        yield 0, j, 1, 0
        yield 0, j, 1, 1
        yield h-1, j, -1, 1

h, w = LI()
aa = LLI(h)
ans = 0
for i, j, di, dj in start():
    for p, q, dp, dq in start():
        if (i, j, di, dj) == (p, q, dp, dq): continue
        cur = line(i, j, di, dj)+line(p, q, dp, dq)
        ci, cj = cross(i, j, di, dj, p, q, dp, dq)
        if ci != -1: cur -= aa[ci][cj]
        if cur > ans: ans = cur
        # print(ans, i, j, di, dj, p, q, dp, dq)

print(ans)