#include <iostream>
#include <iomanip>
#include <algorithm>
#include <complex>
#include <utility>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <tuple>
#include <cmath>
#include <bitset>
#include <cctype>
#include <set>
#include <map>
#include <unordered_map>
#include <numeric>
#include <functional>
#define _overload3(_1,_2,_3,name,...) name
#define _rep(i,n) repi(i,0,n)
#define repi(i,a,b) for(ll i=ll(a);i<ll(b);++i)
#define rep(...) _overload3(__VA_ARGS__,repi,_rep,)(__VA_ARGS__)
#define all(x) (x).begin(),(x).end()
#define PRINT(V) cout << V << "\n"
#define SORT(V) sort((V).begin(),(V).end())
#define RSORT(V) sort((V).rbegin(), (V).rend())
using namespace std;
using ll = long long;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
inline void Yes(bool condition){ if(condition) PRINT("Yes"); else PRINT("No"); }
template<class itr> void cins(itr first,itr last){
    for (auto i = first;i != last;i++){
        cin >> (*i);
    }
}
template<class itr> void array_output(itr start,itr goal){
    string ans = "",k = " ";
    for (auto i = start;i != goal;i++) ans += to_string(*i)+k;
    if (!ans.empty()) ans.pop_back();
    PRINT(ans);
}
ll gcd(ll a, ll b) {
    return a ? gcd(b%a,a) : b;
}
const ll INF = 1e15;
const ll MOD = 1000000007;
const ll MOD2 = 998244353;
typedef pair<ll,ll> P;
const ll MAX = 200010;
constexpr ll nx[8] = {1,0,-1,0,-1,-1,1,1};
constexpr ll ny[8] = {0,1,0,-1,-1,1,-1,1};
class UnionFind{
    private:
        vector<ll> par;
        vector<ll> siz;
        vector<vector<ll>> nodes;
    public:
        UnionFind(ll sz){
            par.resize(sz);
            siz.assign(sz,1LL);
            nodes.resize(sz);
            rep(i,sz){
                par[i] = i;
                nodes[i].push_back(i);
            }
        }

        ll find(ll x){
            if (par[x] == x) return x;
            else return par[x] = find(par[x]);
        }

        void unite(ll x,ll y){
            x = find(x);
            y = find(y);
            if (x == y) return;
            if (siz[x] < siz[y]) swap(x,y);
            rep(i,siz[y]){
                nodes[x].push_back(nodes[y][i]);
            }
            siz[x] += siz[y];
            par[y] = x;
        }

        bool same(ll x,ll y){
            return find(x) == find(y);
        }

        ll size(ll x){
            return siz[find(x)];
        }

        vector<vector<ll>> give(){
            return nodes;
        }
};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n,a,b;
    cin >> n;
    vector<vector<ll>> x(100001),y(100001);
    vector<P> node(n);
    rep(i,n){
        cin >> a >> b;
        node[i] = P(a,b);
        x[a].push_back(i);
        y[b].push_back(i);
    }
    UnionFind g(n);
    rep(i,1,100001){
        rep(j,x[i].size()-1){
            g.unite(x[i][j],x[i][j+1]);
        }
        rep(j,y[i].size()-1){
            g.unite(y[i][j],y[i][j+1]);
        }
    }
    vector<vector<ll>> nodes = g.give();
    vector<bool> done(n,0);
    ll ans = 0;
    rep(i,n){
        ll p = g.find(i);
        vector<bool> dx(100001,0),dy(100001,0);
        if (done[p]) continue;
        done[p] = 1;
        ll cx = 0,cy = 0;
        for (ll v:nodes[p]){
            tie(a,b) = node[v];
            if (!dx[a]){
                cx++;
                dx[a] = 1;
            }
            if (!dy[b]){
                cy++;
                dy[b] = 1;
            }
        }
        ans += cx*cy;
    }
    PRINT(ans-n);
}


Measured memory_bytes: 31980