#include <bits/stdc++.h> using namespace std; #define int long long #define ld long double #define pii pair<int, int> #define fi first #define se second #define __builtin_popcount __builtin_popcountll #define all(x) (x).begin(), (x).end() #define debug(a, l, r) for (int i = (l); i <= (r); ++i) cout << (a)[i] << ' '; cout << '\n'; const int MAXN = 3e5 + 5; int n, x[MAXN], y[MAXN]; map<int, int> cntx, cnty; map<pii, int> cnt; signed main() { #ifdef NCTHANH freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); #endif ios_base::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); cin >> n; for (int i = 1; i <= n; ++i) { cin >> x[i] >> y[i]; cntx[x[i]]++; cnty[y[i]]++; cnt[{x[i], y[i]}]++; } int res = 0; for (int i = 1; i <= n; ++i) { int cx = cntx[x[i]] - cnt[{x[i], y[i]}]; int cy = cnty[y[i]] - cnt[{x[i], y[i]}]; res += cx * cy; } cout << res; return 0; }