#include <bits/stdc++.h>
using namespace std;
/// toto -> 1
#define pb push_back
#define pii pair<int,int>
#define pll pair<ll,ll>
#define io \
ios_base::sync_with_stdio(0); \
cin.tie(0); \
cout.tie(0);
#define all(a) a.begin(),a.end()
#define rep(k,i,n) for(int k=i;k<n;k++)
#define repp(k,i,n) for(int k=n-1;k>=i;k--)
#define rech(k) for(char k='a';k<='z';k++)
#define SZ(a) (int)a.size()
#define MX(a) *max_element(all(a))
#define MN(a) *min_element(all(a))
#define SM(a) accumulate(all(a),0LL)
#define vi vector<int>
#define vl vector<long long>
#define vvl vector<vector<long long>>
#define vvi vector<vector<int>>
/// toto -> 2
const int mod = 1e9 + 7 , modd = 998244353;
void F1(bool res) {
if(res) {
cout<<"YES\n" ;
}
else {
cout<<"NO\n" ;
}
}
struct mint{
int val;
mint(int64_t v = 0) {
v %= mod;
if (v < 0) v += mod;
val = v;
}
mint& operator+=(const mint& other) {
val += other.val;
if (val >= mod) val -= mod;
return *this;
}
mint& operator-=(const mint& other) {
val += mod - other.val;
if (val >= mod) val -= mod;
return *this;
}
mint& operator*=(const mint& other) {
val = (int64_t)val * other.val % mod;
return *this;
}
mint& operator/=(const mint& other) {
return *this *= other.inv();
}
friend mint operator+(mint a, const mint& b) { return a += b; }
friend mint operator-(mint a, const mint& b) { return a -= b; }
friend mint operator*(mint a, const mint& b) { return a *= b; }
friend mint operator/(mint a, const mint& b) { return a /= b; }
mint pow(int64_t exp) const {
mint a = *this, res = 1;
while (exp > 0) {
if (exp & 1)
res *= a;
a *= a;
exp >>= 1;
}
return res;
}
mint inv() const {
assert(val != 0);
return pow(mod - 2);
}
friend ostream& operator<<(ostream& os, const mint& m) {
return os << m.val;
}
};
int bp(int n,int m){
if(m == 0){
return 1;
}
if(m == 1){
return n%mod;
}
if(m%2==0){
return bp(n*n%mod,m/2);
}
return n*bp(n,m-1)%mod;
}
typedef long long ll;
/// toto -> 3
const int N = 2e5 + 546, M = 2e3 + 5 , inf = 2e9 + 99;
const ll inff = 1e18 + 88;
void solve(){
int n;
cin>>n;
vi x(n) , y(n);
map<int,int>m1,m2;
rep(i,0,n){
cin>>x[i]>>y[i];
m1[x[i]]++;
m2[y[i]]++;
}
ll res = 0;
rep(i,0,n){
res += (m1[x[i]] - 1)*(m2[y[i]] - 1);
}
cout << res;
}
int32_t main()
{
io;
ll t=1;
/// cin>>t;
rep(_,1,t+1)
{
cerr << "Start of test case " << _ << "\n";
///cout<<"Case #"<<_<<": ";
solve();
cerr << endl;
cerr << endl;
}
return 0;
}
