pending = []
n = int(input())
s = [input() for _ in range(n)]
for i in range(n):
    for j in range(i):
        if s[i][j] == '-':
            pending.append((i, j))
def calc_score(s):
    wincnt = [si.count('o') for si in s]
    t = wincnt[0]
    ret = 1
    for x in set(wincnt):
        if x > t:
            ret += 1
    return ret
if not pending:
    print(calc_score(s))
    exit(0)
ans = n
for b in range(1 << len(pending)):
    stmp = [list(si) for si in s]
    for k, (i, j) in enumerate(pending):
        if b >> k & 1:
            stmp[i][j] = 'o'
        else:
            stmp[j][i] = 'o'
    ans = min(ans, calc_score(stmp))
print(ans)