#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 3e5+10;
const int MAXA = 2e3+10;
const int INF = 1e18+10;
const int LOG = 19;
const int MOD = 1e9+7;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};
int n;
int x[MAXN], y[MAXN];
map <int, int> p, q;
signed main(){
// ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n;
for(int i=1; i<=n; i++){
cin >> x[i] >> y[i];
p[x[i]]++; q[y[i]]++;
}
int ans = 0;
for(int i=1; i<=n; i++){
ans += (p[x[i]]-1) * (q[y[i]]-1);
}
cout << ans << '\n';
}
