#include<algorithm> #include<iostream> #include<vector> #include<string> #include<random> #include<cmath> #include<stack> #include<map> #include <iomanip> #include <queue> #include <set> using namespace std; using ll = long long; using ull = unsigned long long; ll mod = 1e9 + 7; ll pv(ll a, ll b) { if (b == 0)return 1; ll res = (pv(a, b / 2)); if (b % 2) { return (((res * res) % mod) * (a % mod)) % mod; } else { return (res * res) % mod; } } void solve() { ll n; cin >> n; vector<ll>x(n), y(n); map<ll, ll>mp, mp1; for (ll i = 0; i < n; i++) { cin >> x[i] >> y[i]; mp[x[i]]++; mp1[y[i]]++; } ll ans = 0; for (int i = 0; i < n; i++) { ans += ((mp[x[i]] - 1) * (mp1[y[i]] - 1)); } cout << ans << endl; } signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cin.tie(nullptr); ll _ = 1; //cin >> _; while (_--) { solve(); } }