Envío 1491

Código

import math
[r, c] = map(int, input().split())
m = []
for i in range(0, r):
    m += list(map(int, input().split(" ")))

max_sum = -math.inf

for r1 in range(0, r):
    for c1 in range(0, c):
        sub_sum = 0
        for r2 in range(r1, r):
            for c2 in range(c1, c):
                sub_sum += m[r2 * c + c2]
        max_sum = max(max_sum, sub_sum)
for r1 in range(1, r + 1):
    for c1 in range(1, c + 1):
        sub_sum = 0
        for r2 in range(0, r1):
            for c2 in range(0, c1):
                sub_sum += m[r2 * c + c2]
        max_sum = max(max_sum, sub_sum)
max_sum = max(max_sum, max(m))
print(max_sum)