#include <bits/stdc++.h>
using namespace std;
pair<int, bool> convert(string s) {
  int hour = 0;
  bool ap;
  if (s[1] == '1' && s[2] == '2') {
    s[1] = '0';
    s[2] = '0';
  }
  hour = (int)s[1] - '0';
  hour = 10 * hour + (int)s[2] - '0';
  hour = 10 * hour + (int)s[4] - '0';
  hour = 10 * hour + (int)s[5] - '0';
  if (s[7] == 'a')
    ap = false;
  else
    ap = true;
  return make_pair(hour, ap);
}
int main() {
  string s;
  int n;
  vector<pair<int, bool> > v;
  cin >> n;
  getline(cin, s);
  for (int i = 0; i < n; i++) {
    getline(cin, s);
    v.push_back(convert(s));
  }
  int count = 1;
  int ten = 0;
  for (int i = 0; i < v.size() - 1; i++) {
    if (v[i + 1].first == v[i].first && v[i + 1].second == v[i].second)
      ten++;
    else
      ten = 0;
    if (v[i + 1].second == false && v[i].second == true)
      count++;
    else if (v[i + 1].second == v[i].second && v[i + 1].first < v[i].first)
      count++;
    if (ten == 10) {
      count++;
      ten = 0;
    }
  }
  cout << count << endl;
  return 0;
}
