n = int(input())
s = [input().strip() for _ in range(n)]

initial_wins = [0] * n
for i in range(n):
    for j in range(n):
        if i == j:
            continue
        if s[i][j] == 'o':
            initial_wins[i] += 1

remaining_games = []
for i in range(n):
    for j in range(i + 1, n):
        if s[i][j] == '-':
            remaining_games.append((i, j))

m = len(remaining_games)
min_rank = n  # Initialize with the worst possible rank

for mask in range(0, 1 << m):
    additional = [0] * n
    for game_index in range(m):
        i, j = remaining_games[game_index]
        if mask & (1 << game_index):
            additional[j] += 1
        else:
            additional[i] += 1
    total = [initial_wins[k] + additional[k] for k in range(n)]
    unique_wins = sorted(list(set(total)), reverse=True)
    team0_win = total[0]
    current_rank = None
    for idx, w in enumerate(unique_wins):
        if w == team0_win:
            current_rank = idx + 1
            break
    if current_rank < min_rank:
        min_rank = current_rank

print(min_rank)