#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define pb push_back
#define sz(v) (ll)(v.size())
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.end()
#define f first
#define s second
#define pll pair<ll, ll>
#define pii pair<int, int>
using namespace std;
using namespace __gnu_pbds;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update>ordered_set;
void solve()
{
ll n, i, j;
cin >> n;
map<ll, ll>mpx, mpy;
vector<pll>vect;
map<pll, ll>mp;
for(i = 1; i <= n; i++)
{
ll x, y;
cin >> x >> y;
if(mp.find({x, y}) == mp.end())
vect.pb({x, y}), mpx[x]++, mpy[y]++;
mp[{x, y}]++;
}
ll res = 0;
for(auto u : vect)
res += mp[u] * ((mpx[u.f] - 1) * (mpy[u.s] - 1));
cout << res << "\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll tests = 1;
//cin >> tests;
while(tests--)
{
solve();
}
}
