#include <bits/stdc++.h>   using namespace std;   vector<pair<string, string>> taken;   int main() {     int n;     scanf( %d , &n);     int ans = 0;     for (int i = 1; i <= n; ++i) {       string s, t;       cin >> s >> t;       bool flag = 1;       for (auto [x, y] : taken) {         if (x == s && y == t) {           flag = 0;           break;         }       }       if (flag) {         ans++;         taken.push_back({s, t});       }     }     printf( %d n , ans);   }   