6. 격자판 최대합

# 격자판 최대합

def run(N, mp):
    max_s = 0
    for i in range(N):
        s1 = s2 = 0
        for j in range(N):
            s1 += mp[i][j]
            s2 += mp[j][i]
        max_s = max(max_s, s1)
        max_s = max(max_s, s2)

    s1 = s2 = 0
    for i in range(N):
        s1 += mp[i][i]
        s2 += mp[i][-1-i]
    max_s = max(max_s, s1)
    max_s = max(max_s, s2)

    return max_s


N = int(input())
mp = [list(map(int, input().split())) for _ in range(N)]
print(run(N, mp))