#include <algorithm>
#include <iostream>
#include <numeric>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#define rep(i, a, b) for (int i = int(a); i < int(b); i++)
using namespace std;
using ll = long long int;
using P = pair<ll, ll>;

// clang-format off
#ifdef _DEBUG_
#define dump(...) do{ cerr << __LINE__ << ":\t" << #__VA_ARGS__ << " = "; debug_print(__VA_ARGS__); } while(false)
template<typename T, typename... Ts> void debug_print(const T &t, const Ts &...ts) { cerr << t; ((cerr << ", " << ts), ...); cerr << endl; }
#else
#define dump(...) do{ } while(false)
#endif
template<typename T> vector<T> make_v(size_t a, T b) { return vector<T>(a, b); }
template<typename... Ts> auto make_v(size_t a, Ts... ts) { return vector<decltype(make_v(ts...))>(a, make_v(ts...)); }
template<typename T> bool chmin(T &a, const T& b) { if (a > b) {a = b; return true; } return false; }
template<typename T> bool chmax(T &a, const T& b) { if (a < b) {a = b; return true; } return false; }
template<typename T, typename... Ts> void print(const T& t, const Ts&... ts) { cout << t; ((cout << ' ' << ts), ...); cout << '\n'; }
template<typename... Ts> void input(Ts&... ts) { (cin >> ... >> ts); }
template<typename T> istream &operator,(istream &in, T &t) { return in >> t; }
// clang-format on

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    cin, n;
    auto mp = make_v(n, n, '#');
    rep(i, 0, n) {
        rep(j, 0, n) {
            cin, mp[i][j];
        }
    }
    int bits = 0;
    rep(i, 0, n) {
        rep(j, i + 1, n) {
            bits += (mp[i][j] == '-');
        }
    }

    auto check = [&](const auto &vec) {
        vector<int> win(n, 0);
        rep(i, 0, n) {
            rep(j, 0, n) {
                win[i] += vec[i][j] == 'o';
            }
        }
        vector<bool> used(n, false);
        int rank = 1;
        rep(i, 1, n) {
            if (used[win[i]]) continue;
            used[win[i]] = true;
            rank += (win[0] < win[i]);
        }
        return rank;
    };

    string ox = "ox";

    int ans = 1 << 30;
    if (bits == 0) {
        ans = check(mp);
    }

    rep(bit, 0, 1 << bits) {
        auto cp = mp;
        int tmp = bit;
        rep(i, 0, n) {
            rep(j, i + 1, n) {
                if (cp[i][j] == '-') {
                    cp[i][j] = ox[tmp & 1];
                    cp[j][i] = ox[!(tmp & 1)];
                    tmp >>= 1;
                }
            }
        }
        chmin(ans, check(cp));
    }
    print(ans);

    return 0;
}