#include<bits/stdc++.h>
#define x first
#define y second
#define pb push_back
#define mp make_pair
#define up_b upper_bound
#define low_b lower_bound
#define sz(x) (int)x.size()
#define all(v) v.begin(),v.end()
#define boost ios_base::sync_with_stdio(0),cin.tie(0),cout.tie()
using namespace std;
typedef unsigned long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<int,ll> pil;
typedef pair<ll,int> pli;
typedef pair<ll,ll> pll;
const ll INF = 1e18;
const int inf = INT_MAX;
const ll mod = 1e9 + 7;
const int pi = acos(-1);
const int dx[4] = {0, 1, 0, 0};
const int dy[4] = {1, 0, 0, 0};
const int N = 1e5 + 5;
const int MAXN = 1e6 + 1;
int x[3 * N], y[3 * N];
map < int, int > cnt1, cnt2;
int main(){
int n;
cin >> n;
for(int i = 1; i <= n; i++){
cin >> x[i] >> y[i];
cnt1[x[i]]++;
cnt2[y[i]]++;
}
ll ans = 0;
for(int i = 1; i <= n; i++){
ans += 1LL * (cnt1[x[i]] - 1) * (cnt2[y[i]] - 1);
}
cout << ans;
}
