#include <bits/stdc++.h>
using namespace std;
template <typename T>
void print1d(vector<T> &a) {
  for (long long int i = 0; i < a.size(); i++) {
    cout << a[i] << " ";
  }
  cout << endl;
}
vector<long long int> divisor(long long int n) {
  vector<long long int> a;
  for (long long int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      if (n / i == i)
        a.push_back(i);
      else {
        a.push_back(i);
        a.push_back(n / i);
      }
    }
  }
  return a;
}
bool sortsecond(const pair<long long int, long long int> &a,
                const pair<long long int, long long int> &b) {
  return a.second < b.second;
}
bool isPrime(long long int n) {
  for (long long int i = 2; i * i <= n; i++) {
    if (n % i == 0) return false;
  }
  return true;
}
vector<string> split_string(const string &s, const string &delimiter) {
  vector<string> token;
  string ans;
  size_t end_point, start_point = 0, delim_length = delimiter.length();
  while ((end_point = s.find(delimiter, start_point)) != string::npos) {
    ans = s.substr(start_point, end_point - start_point);
    start_point = end_point + delim_length;
    token.push_back(ans);
  }
  token.push_back(s.substr(start_point));
  return token;
}
bool is_vowel(const char &a) {
  switch (a) {
    case 'a':
    case 'e':
    case 'i':
    case 'o':
    case 'u':
    case 'A':
    case 'E':
    case 'I':
    case 'O':
    case 'U':
      return true;
      break;
    default:
      return false;
      break;
  }
}
bool sortstring(const string &a, const string &b) {
  return a.length() < b.length();
}
void solve() {
  long long int n;
  cin >> n;
  vector<string> s(n);
  for (long long int i = 0; i < n; i++) {
    cin >> s[i];
  }
  long long int ans = 0;
  unordered_set<long long int> e;
  for (long long int i = 0; i < n; i++) {
    long long int cnt = 1;
    e.clear();
    for (long long int j = 0; j < n; j++) {
      if (s[i][j] == '1') e.insert(j);
    }
    long long int k = i;
    bool flag = true;
    for (long long int i = 0; i < n; i++) {
      if (k == i) continue;
      flag = true;
      for (long long int j = 0; j < n; j++) {
        if (e.find(j) == e.end() && s[i][j] == '0')
          continue;
        else if (e.find(j) != e.end() && s[i][j] == '1')
          continue;
        flag = false;
        break;
      }
      if (flag) cnt++;
    }
    ans = max(ans, cnt);
  }
  cout << ans << endl;
  return;
}
int32_t main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  ;
  solve();
  return 0;
}
