import sys
sys.stdin=open('input.txt','r')
defsolution(board):
rows_sum=[sum(arr) for arr in board]
cols_sum=[sum(arr) for arr inzip(*board)]
digs_sum=[sum(board[i][i] for i inrange(N)),
sum(board[i][N-i-1] for i inrange(N))]
returnmax(rows_sum+cols_sum+digs_sum)
if __name__=="__main__":
N=int(input())
board=[list(map(int, input().split())) for _ inrange(N)]
print(solution(board))