#include <bits/stdc++.h> using namespace std; #define endl '\n' #define f first // #define s second #define pb(x) push_back(x) #define int long long /* ORDERED SET PDBS #include <bits/extc++.h> using namespace __gnu_pbds; typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; */ const int MOD = 1e9+7; const int inf = 1e9; const int INF = 1e18+20; const int LOG = 25; void solve() { int n; cin>>n; set<int> cords; for (int i=0; i<n; i++) { int x, e; cin>>x>>e; cords.insert(x); } cout<<cords.size()<<endl; } bool multi=false; int32_t main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int t=1; if (multi) cin>>t; while (t--) solve(); return 0; }