#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
#define INF 1000000021
#define MOD 1000000007
#define pb push_back
#define sqr(a) (a)*(a)
#define M(a, b) make_pair(a,b)
#define T(a, b, c) make_pair(a, make_pair(b, c))
#define F first
#define S second
#define all(x) (x.begin(), x.end())
#define deb(x) cerr << #x << " = " << x << '\n'
#define N 322222
using namespace std;
//using namespace __gnu_pbds;
typedef long double ld;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
const ld pi = 2 * acos(0.0);
template<class T> bool umin(T& a, T b){if(a>b){a=b;return 1;}return 0;}
template<class T> bool umax(T& a, T b){if(a<b){a=b;return 1;}return 0;}
template<class T, class TT> bool pal(T a, TT n){int k=0;for(int i=0;i<=n/2;i++){if(a[i]!=a[n-i-1]){k=1;break;}}return k?0:1;}
//int month[] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
ll a[N], b[N];
map<ll, ll> x, y;
int main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
// freopen("triangles.in", "r", stdin);
// freopen("triangles.out", "w", stdout);
int n;
cin >> n;
for(int i = 1; i <= n; i ++)
{
ll xx, yy;
cin >> xx >> yy;
x[xx] ++;
y[yy] ++;
a[i] = xx;
b[i] = yy;
}
ll ans = 0;
for(int i = 1; i <= n; i ++)
ans += ((x[a[i]]-1)*(y[b[i]]-1));
cout << ans;
getchar();
getchar();
return 0;
}
