# -*- coding: utf-8 -*-
"""
No.43 野球の試合
https://yukicoder.me/problems/no/43

"""
import sys
from sys import stdin
from copy import deepcopy
input = stdin.readline


def update_status(i, result, remaining):
    t = list(bin(i).zfill(len(remaining))[2:])
    for r, win_lose in zip(remaining, t):
        x, y = r[0], r[1]
        if win_lose == '1':
            result[y][x] = 'o'
            result[x][y] = 'x'
        else:
            result[y][x] = 'x'
            result[x][y] = 'o'


def solve(N, status):
    remaining = []
    for y in range(N):
        for x in range(y+1, N):
            if status[y][x] == '-':
                remaining.append([x, y])

    best_rank = N
    for i in range(2**len(remaining)):
        result = deepcopy(status)
        update_status(i, result, remaining)
        best_rank = min(best_rank, check_rank(N, result))
    return best_rank



def check_rank(N, result):
    # 他チームの勝ち星数をチェック
    winnings = []
    for r in result[1:]:
        w = r.count('o')
        if w not in winnings:
            winnings.append(w)
    # 自分のチームの勝ち星数と比較して順位を決定する
    my_winning = result[0].count('o')
    ans = 1
    for w in winnings:
        if w > my_winning:
            ans += 1
    return ans


def main(args):
    N = int(input())
    status = []
    for _ in range(N):
        status.append(list(input().strip()))

    ans = solve(N, status)
    print(ans)


if __name__ == '__main__':
    main(sys.argv[1:])