#include <bits/stdc++.h>
using namespace std;
struct p {
  string c, d;
} a[105];
int main() {
  int flag[105] = {0};
  int n, ans = 0;
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i].c >> a[i].d;
  for (int i = 1; i <= n; i++)
    for (int j = i + 1; j <= n; j++)
      if ((a[i].c == a[j].c) && (a[i].d == a[j].d) &&
          ((flag[i] != 1) || (flag[j] != 1))) {
        ans++;
        flag[i] = 1;
        flag[j] = 1;
      }
  cout << n - ans;
  return 0;
}
