#include <bits/stdc++.h>
#define INF 1000000021
#define MOD 1000000007
#define pb push_back
#define sqr(a) (a)*(a)
#define M(a, b) make_pair(a,b)
#define int long long
#define T(a, b, c) make_pair(a, make_pair(b, c))
#define F first
#define S second
#define all(x) sort(x.begin(), x.end())
#define rall(x) sort(x.rbegin(), x.rend())
#define deb(x) cerr << #x << " = " << x << '\n'
#define N 222222
using namespace std;
//using namespace __gnu_pbds;
typedef long double ld;
typedef pair<int,int> pii;
typedef vector<int> vi;
//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
const ld pi = 2 * acos(0.0);
//int month[] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
int gcd(int a, int b) {
return b ? gcd (b, a % b) : a;
}
int binpow (int a, int n) {
if (n == 0)
return 1LL;
if (n % 2 == 1)
return ((binpow (a, n-1)%MOD) * 1LL * a)%MOD;
else {
int b = binpow (a, n/2)%MOD;
return (b * b)%MOD;
}
}
//void swap(int &a, int &b){
// b = (a+b) - (a=b);
//}
void solve(){
map<int, int> m1, m2;
int n, a[300001][2], sum = 0;
cin >> n;
for(int i = 0; i < n; i++){
cin >> a[i][0] >> a[i][1];
m1[a[i][0]]++;
m2[a[i][1]]++;
}
for(int i = 0; i < n; i++){
sum += (m1[a[i][0]] - 1) * (m2[a[i][1]] - 1);
}
cout << sum;
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while(t--){
solve();
cout << "\n";
}
return 0;
}
