#include <bits/stdc++.h>
using namespace std;
string s, h1, m1;
int h[10000], m[10000];
bool a[10000];
int main() {
  int n;
  cin >> n;
  cin.ignore();
  for (__typeof(n) i = (1); i <= (n); i++) {
    getline(cin, s);
    h1 = s.substr(1, 2);
    m1 = s.substr(4, 2);
    if (s[7] == 'a')
      a[i] = true;
    else
      a[i] = false;
    stringstream sh, sm;
    sh.flush();
    sm.flush();
    sh.clear();
    sm.clear();
    sh << h1;
    sm << m1;
    sh >> h[i];
    sm >> m[i];
    h[i] %= 12;
    if (!a[i]) h[i] += 12;
  }
  int ans = 1;
  int k = 0;
  for (__typeof(n - 1) i = (1); i <= (n - 1); i++) {
    int t1 = h[i] * 10000 + m[i];
    int t2 = h[i + 1] * 10000 + m[i + 1];
    if (t1 == t2)
      k++;
    else
      k = 0;
    if (k == 10) {
      k = 0;
      ans++;
      continue;
    }
    if (!(a[i]) && a[i + 1]) {
      ans++;
      continue;
    }
    if (t1 > t2) {
      ans++;
    }
  }
  cout << ans << endl;
  return 0;
}
