#include <bits/stdc++.h> using namespace std; template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; } template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; } #define ll long long #define ld long double #define all(a) (a).begin(), (a).end() #define sui cout.tie(NULL); cin.tie(NULL); ios_base::sync_with_stdio(false) const int MAX_N = 1e5 + 5; const int MOD = 1e9 + 7; const ll INF = 1e9; const ld EPS = 1e-9; const int LOG = 30; void solve() { int n; cin >> n; map<int, int> x, y; vector<pair<int, int>> al; for (int i = 0; i < n; i++) { int x1, y1; cin >> x1 >> y1; al.push_back({x1, y1}); x[x1]++; y[y1]++; } ll ans = 0; for (auto xx : al) ans += 1ll * (x[xx.first] - 1) * (y[xx.second] - 1); cout << ans << "\n"; } int main() { sui; int tc = 1; //cin >> tc; for (int t = 1; t <= tc; t++) { solve(); } }