#include <bits/stdc++.h>
using namespace std;
int n, ans;
struct leaves {
  string tree, color;
} l[110];
int main() {
  cin >> n;
  ans = n;
  for (int i = 0; i < n; ++i) {
    cin >> l[i].tree >> l[i].color;
    for (int j = 0; j < i; ++j) {
      if (l[j].color == l[i].color && l[j].tree == l[i].tree) {
        --ans;
        break;
      }
    }
  }
  cout << ans << endl;
  return 0;
}
