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

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

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

m = len(remaining)
best_rank = n  # Initialize with the worst possible rank

for mask in range(1 << m):
    wins = current_wins.copy()
    for k in range(m):
        i, j = remaining[k]
        if (mask >> k) & 1:
            wins[j] += 1
        else:
            wins[i] += 1
    target = wins[0]
    sorted_wins = sorted(wins, reverse=True)
    rank = 1
    for w in sorted_wins:
        if w > target:
            rank += 1
        else:
            break
    if rank < best_rank:
        best_rank = rank

print(best_rank)