import copy
N = int(input())
lsS = [list(input()) for i in range(N)]
'''
for i in range(1,N):
    if lsS[0][i] == '-':
        lsS[0][i] = 'o'
        lsS[i][0] = 'x'
'''
lsmi = []
for i in range(N-1):
    for j in range(i+1,N):
        if lsS[i][j] == '-':
            lsmi.append((i,j))
M = len(lsmi)
ans = 10
for i in range(2**M):
    lsS1 = copy.deepcopy(lsS)
    for j in range(M):
        if (i >> j)&1:
            a,b = lsmi[j]
            lsS1[a][b] = 'o'
            lsS1[b][a] = 'x'
        else:
            a,b = lsmi[j]
            lsS1[b][a] = 'o'
            lsS1[a][b] = 'x'
    ls = []
    for i in range(N):
        ls.append((lsS1[i].count('o'),i))
    ls.sort(reverse=True)
    cnt = 0
    win = 100
    lsrank = [0]*(N)
    for i in range(N):
        if win != ls[i][0]:
            cnt += 1
            lsrank[ls[i][1]] = cnt
            win = ls[i][0]
        else:
            lsrank[ls[i][1]] = cnt
    ans = min(lsrank[0],ans)
print(ans)