def collect_max_nuts(n, forest):
    max_nuts = 0
    max_dist = [[min(i, n - 1 - i) + min(j, n - 1 - j) for j in range(n)] for i in range(n)]
 
    for i in range(n):
        for j in range(n):
            nuts = forest[i][j]
 
            for x in range(n):
                for y in range(n):
                    dist = abs(i - x) + abs(j - y)
                    if dist <= max_dist[i][j]:
                        nuts += forest[x][y]
 
            max_nuts = max(max_nuts, nuts)
 
    return max_nuts
 
# Read input
n = int(input())
forest = [list(map(int, input().split())) for _ in range(n)]
 
# Find the maximum number of nuts the squirrel can collect
max_nuts = collect_max_nuts(n, forest)
print(max_nuts)