import copy

N = int(input())
s = [input() for _ in range(N)]

a = []
b = []
win = [0] * N
for i in range(N):
    for j in range(i):
        if s[i][j] == '-':
            a.append(i)
            b.append(j)
        elif s[i][j] == 'o':
            win[i] += 1
        else:
            win[j] += 1

ans = N
for i in range(1 << len(a)):
    wintemp = copy.deepcopy(win)
    for j in range(len(a)):
        if (i >> j) % 2 == 0:
            wintemp[a[j]] += 1
        else:
            wintemp[b[j]] += 1

    for j in range(N):
        wintemp[j] = wintemp[j] * N + j

    wintemp.sort()
    wintemp = wintemp[::-1]

    place = 0
    prepoint = -1
    for j in range(N):
        winnum = wintemp[j] // N
        team = wintemp[j] % N
        if prepoint != winnum:
            prepoint = winnum
            place += 1

        if team == 0:
            ans = min(place, ans)

print(ans)