#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
// author : AtabeyR
#define pb push_back
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(v) v.begin(), v.end()
#define OPT ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define sec second
#define fi first
#define int ll
#define print(k) cerr << "Ans : "; cout << k << endl;
#define ins insert
#define bpc __builtin_popcountll
#define skip continue
#define endll "\n"
#define li 2*ind+1
#define ri 2*ind+2
#define lb lower_bound
#define ub upper_bound
typedef long long ll;
typedef unsigned long long ull;
const int oo = 0x3F3F3F3F;
const int ooo = 0x3F3F3F3F3F3F3F3FLL;
const int mod = 998244353;
const int sz = 3e5+6;
using namespace std;
using namespace __gnu_pbds;
template<class T> using ordered_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update>;
int lcm(int a, int b)
{
return a*b / (__gcd(a, b));
}
int gcd(int a, int b)
{
return __gcd(a, b);
}
int n, m, k;
void proud(int balls)
{
cin >> n;
vector<int> x, y;
map<int, int> mx, my;
map<pii, int> mp;
for(int i = 1; i<=n; i++)
{
int xx, yy;
cin >> xx >> yy;
mx[xx]++;
my[yy]++;
mp[pii(xx, yy)]++;
}
int res = 0;
for(pair<pii, int> p : mp)
{
int c1 = mx[p.fi.fi] - 1;
int c2 = my[p.fi.sec] - 1;
res += c1 * c2 * p.sec;
}
cout << res << endll;
}
int32_t main()
{
// freopen("i.txt", "r", stdin);
// freopen("o.txt", "w", stdout);
OPT
int t = 1;
//cin >> t;
for(int i = 1; i<=t; i++)
proud(i);
}
