//#pragma GCC optomize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse4.1,sse4.2")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define max_heap priority_queue<pair <ll, pair <ll, ll>>>
#define min_heap priority_queue<pair <ll, ll>, vector<pair <ll, ll>>, greater<pair <ll, ll>>>
#define sariE cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define filE freopen("in.txt", "r", stdin);// freopen("out1.txt", "w", stdout);
#define endl '\n'
#define md(a) (a % mod + mod) % mod
#define pb push_back
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//cout << setprecision(5) << fixed << f;
//hash prime = 769
ll const maxn = 3e5 + 123;
ll const inf = 3e18;
ll const loG = 18; // 23
ll const mod = 1e9 + 7;
//ll const mod = 998244353;
ll const sq = 500;
ll power(ll a, ll b, ll mod){if(b==0)return 1;if(b==1)return a;ll x = power(a, b / 2, mod);return (((x * x) % mod) * (b % 2 ? a : 1)) % mod;}
ll n, point[maxn][2], cnt[maxn * 2], ans;
vector <ll> cmp, arr[maxn * 2];
void Solve(){
cin >> n;
for (int i = 1; i < n + 1; i++){
cin >> point[i][0] >> point[i][1];
cmp.pb(point[i][0]);
cmp.pb(point[i][1]);
}
sort(cmp.begin(), cmp.end()); cmp.resize(unique(cmp.begin(), cmp.end()) - cmp.begin());
for (int i = 1; i < n + 1; i++){
point[i][0] = lower_bound(cmp.begin(), cmp.end(), point[i][0]) - cmp.begin();
point[i][1] = lower_bound(cmp.begin(), cmp.end(), point[i][1]) - cmp.begin();
arr[point[i][0]].pb(point[i][1]);
cnt[point[i][1]]++;
}
for (int i = 0; i < maxn * 2; i++){
ll t = arr[i].size();
for (ll x : arr[i]){
//cout << i << ' ' << x << " " << cnt[x] << endl;
ans += (t - 1) * (cnt[x] - 1);
}
}
cout << ans << endl;
}
int main(){
sariE;
//filE;
int test = 1;
//cin >> test;
while (test--) Solve();
return 0;
}
