import sys
import pypyjit
import itertools
import heapq
import math
from collections import deque, defaultdict
import bisect

input = sys.stdin.readline
sys.setrecursionlimit(10 ** 6)
pypyjit.set_param('max_unroll_recursion=-1')


def index_lt(a, x):
    'return largest index s.t. A[i] < x or -1 if it does not exist'
    return bisect.bisect_left(a, x) - 1


def index_le(a, x):
    'return largest index s.t. A[i] <= x or -1 if it does not exist'
    return bisect.bisect_right(a, x) - 1


def index_gt(a, x):
    'return smallest index s.t. A[i] > x or len(a) if it does not exist'
    return bisect.bisect_right(a, x)


def index_ge(a, x):
    'return smallest index s.t. A[i] >= x or len(a) if it does not exist'
    return bisect.bisect_left(a, x)


N = int(input())
S = [input()[:-1] for _ in range(N)]
rest = 0
for s in S:
    rest += s.count('-')
rest //= 2

ans = N
for s in range(1 << rest):
    cnt = 0
    A = [[None for _ in range(N)] for _ in range(N)]
    for i in range(N):
        for j in range(i, N):
            if S[i][j] == '-':
                A[i][j] = 'o' if s & (1 << cnt) else 'x'
                cnt += 1
            else:
                A[i][j] = S[i][j]
    for i in range(N):
        for j in range(i):
            if S[i][j] == '-':
                A[i][j] = 'x' if A[j][i] == 'o' else 'o'
            else:
                A[i][j] = S[i][j]
    wins = set()
    w0 = A[0].count('o')
    for i in range(N):
        wins.add(A[i].count('o'))
    acc = 1
    for w in wins:
        if w > w0:
            acc += 1
    ans = min(ans, acc)
print(ans)