#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
using namespace std;
using ll = long long;
const int INF = 1000000000;
const int MOD = 1000000007;
const ll llINF = 1000000000000000000;

// #include <atcoder/all>
// using namespace atcoder;
// #include <boost/multiprecision/cpp_int.hpp>
// using lll = boost::multiprecision::cpp_int;
// {{oya, dep}, {ko, ko, ko, ...}}
void solve() {
  int n;
  cin >> n;
  vector<string> s(n);
  rep(i, n) cin >> s[i];
  //rep(i, n) cout << s[i] << endl;
  //s.erase(s.begin() + 1);
  //rep(i, n) cout << s[i] << endl;
  for (int i = n - 1; i >= 0; --i) {
    string t = s[i];
    sort(all(t));
    // cout << s[i] << " " << t << endl;
    if (s[i] != t) s.erase(s.begin() + i);
    if (s[i] != t) s[i] = "*";
  }
  sort(all(s));
  string ans = "";
  rep(i, n) {
    if (s[i] == "*") continue;
    if (ans[ans.size() - 1] <= s[i][0]) {
      ans += s[i];
    } else {
      if (s[i].size() > ans.size()) ans = s[i];
    }
  }
  // cout << ans << endl;
  cout << ans.size() << endl;
  // rep(i, n) cout << s[i] << endl;
}

int main() {
  std::cin.tie(nullptr);
  std::ios_base::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(15);
  solve();
  return 0;
}