#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC target ("avx2")
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma comment (linker, "/STACK: 16777216")
#define f first
#define s second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (x).size()
#define pb push_back
#define mp make_pair
#define int long long
using namespace std;
using namespace __gnu_pbds;
template <typename T> inline bool umax(T &a, const T &b) { if(a < b) { a = b; return 1; } return 0; }
template <typename T> inline bool umin(T &a, const T &b) { if(a > b) { a = b; return 1; } return 0; }
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
template <typename T> using oset = tree<T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
const ll mod = 998244353;
const ll base = 1e6 + 5;
const ll inf = 1e18;
const int MAX = 2000;
const int lg = 20;
random_device rd;
mt19937 gen(rd());
uniform_int_distribution<ll> dis(1, inf);
void solve() {
int n;
cin >> n;
vector<int> x(n), y(n);
map<int, int> cntx, cnty;
for(int i = 0; i < n; i++) {
cin >> x[i] >> y[i];
cntx[x[i]]++; cnty[y[i]]++;
}
int ans = 0;
for(int i = 0; i < n; i++) {
ans += (cntx[x[i]] - 1) * (cnty[y[i]] - 1);
}
cout << ans << '\n';
}
signed main() {
//freopen("triangles.in", "r", stdin); freopen("triangles.out", "w", stdout);
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int ttt = 1;
// cin >> ttt;
while(ttt--) {
solve();
}
return 0;
}
