#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
using namespace std;
using namespace __gnu_pbds;
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define f first
#define s second
#define int long long
#define pii pair<int,int>
template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
tree_order_statistics_node_update> ordered_set;
const int inf = 1e17 + 7;
const int mod = 1e9 + 7;
const int md = 998244353;
const int N = 2e5 + 5;
int binpow(int a, int b){
if(b == 0)return 1;
if(b % 2 == 0){
int c = binpow(a,b/2);
return (c*c)%mod;
}
return (binpow(a,b-1)*a)%mod;
}
int divi(int a, int b){
return (a*(binpow(b,mod-2)))%mod;
}
int n,m,k;
void solve(){
cin >> n;
vector<pii>v(n);
for(auto &to:v)cin >> to.f >> to.s;
map<int,int>x;
map<int,int>y;
for(auto to:v){
x[to.f] += 1;
y[to.s] += 1;
}
int ans = 0;
for(auto to:v){
x[to.f] -= 1;
y[to.s] -= 1;
ans += x[to.f] * y[to.s];
x[to.f] += 1;
y[to.s] += 1;
}
cout << ans << "\n";
}
/*
209715
*/
signed main()
{
//~ freopen("triangles.in", "r", stdin);
//~ freopen("triangles.out", "w", stdout);
ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
int tt=1;//cin>>tt;
while(tt--)solve();
}
