#include <bits/stdc++.h>
using namespace std;
#define int long long
#define stoi stoll
using pii=pair<int,int>;
using vi = vector<int>;
using vvi = vector<vi>;
#define all(c) begin(c),end(c)
#define rall(c) rbegin(c),rend(c)
#define fore(x,c) for(auto &&x:c)
#define rep(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define rrep(i, a, n) for(int i=(int)(n-1);i>=a;--i)
#define sz(c) ((int)c.size())
#define contains(c,x) (c.find(x)!=end(c))
#define inseg(l,x,r) ((l)<=(x)&&(x)<(r))
#define dump(...)
#define pb push_back
#define _ 0
const signed INF_=1001001001; const long long INF=1001001001001001001LL;
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
template<class T> ostream& operator<<(ostream &os,const vector<T> &v) {
    for (auto i = begin(v); i != end(v); i++) os<<*i<<(i==end(v)-1?"":" ");return os;}
template<class T> istream& operator>>(istream &is,vector<T> &v) {
    for (auto i = begin(v); i != end(v); i++) is>>*i;return is;}
template<class T,class U> istream& operator>>(istream &is, pair<T,U> &p) {
    is>>p.first>>p.second;return is;}
template<class T, class U> bool chmax(T &a,const U &b){return a<b?a=b,1:0;}
template<class T, class U> bool chmin(T &a,const U &b){return a>b?a=b,1:0;}
template <class T> void psum(T& c) {partial_sum(begin(c), end(c), begin(c));}
template<class T> using heap=priority_queue<T,vector<T>,greater<T>>;
struct before_main_function {
    before_main_function() {
        cin.tie(nullptr); ios::sync_with_stdio(0);
        cout << setprecision(15) << fixed;
        // #define endl "\n"
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

signed main() {
    int N;
    cin >> N;
    vvi row(100005);
    vvi col(100005);
    vi X(N), Y(N);
    rep(i, 0, N) {
        int x, y;
        cin >> x >> y;
        X[i] = x;
        Y[i] = y;
        row[y].push_back(i);
        col[x].push_back(i);
    }

    vector<bool> used(N);
    int ans = 0;
    rep(i, 0, N) {
        if (used[i]) continue;
        
        if (sz(row[Y[i]]) == 1 || sz(col[X[i]]) == 1) {
            continue;
        }

        int cnt_p = 0;
        set<int> r, c;
        queue<int> q;
        q.push(i);
        used[i] = true;
        r.insert(Y[i]);
        c.insert(X[i]);
        while (sz(q)) {
            int idx = q.front(); q.pop();
            dump(idx);
            cnt_p++;

            auto &R = row[Y[idx]];
            while (sz(R)) {
                if (!used[R.back()]) {
                    c.insert(X[R.back()]);
                    r.insert(Y[R.back()]);
                    q.push(R.back());
                    used[R.back()] = true;
                }
                R.pop_back();
            }
            auto &C = col[X[idx]];
            while (sz(C)) {
                if (!used[C.back()]) {
                    c.insert(X[C.back()]);
                    r.insert(Y[C.back()]);
                    q.push(C.back());
                    used[C.back()] = true;
                }
                C.pop_back();
            }
        }

        dump(i, sz(c), sz(r));
        for (auto x : c) {
            dump(x);
        }
        for (auto y : r) {
            dump(y);
        }
        dump(cnt_p);

        ans += sz(r) * sz(c) - cnt_p;
    }
    cout << ans << endl;
    return (0^_^0);
}



Measured memory_bytes: 14848