#include <bits/stdc++.h>
using namespace std;
struct node {
  int h, m;
  int hehe;
} a[110];
int n;
char s[10000];
int main() {
  int i, j;
  while (~scanf("%d", &n)) {
    getchar();
    for (i = 1; i <= n; i++) {
      gets(s);
      a[i].h = (s[1] - '0') * 10 + s[2] - '0';
      a[i].m = (s[4] - '0') * 10 + s[5] - '0';
      if (a[i].h == 12) a[i].h = 0;
      if (s[7] == 'p') {
        a[i].h += 12;
      }
      a[i].hehe = a[i].m + a[i].h * 60;
    }
    int ans = 1, x = a[1].hehe;
    int siz = 1;
    for (i = 2; i <= n; i++) {
      if (a[i].hehe < x)
        siz = 1, ans++;
      else if (a[i].hehe == x)
        siz++;
      else
        siz = 1;
      if (siz > 10) {
        siz = 1;
        ans++;
      }
      x = a[i].hehe;
    }
    printf("%d\n", ans);
  }
  return 0;
}
