# @EXPECTED_RESULTS@: ACCEPTED, TIME_LIMIT_EXCEEDED
n = int(input())
grid = [[int(x) for x in input().split()] for _ in range(n)]
my_team = set()
for _ in range(n//2):
    scores = [(sum(l), i) for i, l in enumerate(grid)]
    my_team.add(max(scores[i] for i in range(n) if i not in my_team)[1])

score = 0
for i in range(n):
    for j in range(i+1, n):
        if i in my_team and j in my_team:
            score += grid[i][j]
        elif i not in my_team and j not in my_team:
            score -= grid[i][j]
print(score)