#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define sar(a,n) cout<<#a<<":";rep(pachico,n)cout<<" "<<a[pachico];cout<<endl

using namespace std;

template<typename S,typename T>auto&operator<<(ostream&o,pair<S,T>p){return o<<"{"<<p.fi<<","<<p.se<<"}";}
template<typename T>auto&operator<<(ostream&o,set<T>s){for(auto&e:s)o<<e<<" ";return o;}
template<typename S,typename T,typename U>
auto&operator<<(ostream&o,priority_queue<S,T,U>q){while(!q.empty())o<<q.top()<<" ",q.pop();return o;}
template<typename K,typename T>auto&operator<<(ostream&o,map<K,T>&m){for(auto&e:m)o<<e<<" ";return o;}
template<typename T>auto&operator<<(ostream&o,vector<T>v){for(auto&e:v)o<<e<<" ";return o;}
void ashow(){cout<<endl;}template<typename T,typename...A>void ashow(T t,A...a){cout<<t<<" ";ashow(a...);}
template<typename S,typename T,typename U>
struct TRI{S fi;T se;U th;TRI(){}TRI(S f,T s,U t):fi(f),se(s),th(t){}};
template<typename S,typename T,typename U>
auto&operator<<(ostream&o,TRI<S,T,U>&t){return o<<"{"<<t.fi<<","<<t.se<<","<<t.th<<"}";}

typedef pair<int, int> P;
typedef pair<ll, ll> pll;
typedef TRI<int, int, int> tri;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<P> vp;
typedef vector<double> vd;
typedef vector<string> vs;

const int MAX_N = 100000;

class UF {
private:
    int sz;
public:
    vector<int> kind;   //所属しているグループ番号
    vector<vector<int> > inc;   //グループのメンバー
    UF(){}
    UF(int node_size){ sz = node_size; kind.resize(sz),inc.resize(sz); rep(i,sz){ kind[i] = i; inc[i].pb(i); } }
    bool same(int a,int b){ return kind[a] == kind[b]; }
    void unite(int a,int b)
    { if(same(a,b)) return; if(inc[kind[a]].size() < inc[kind[b]].size()) swap(a,b);
        int ga = kind[a],gb = kind[b]; rep(i,inc[gb].size()) kind[inc[gb][i]] = ga;
        inc[ga].insert(inc[ga].end(),inc[gb].begin(),inc[gb].end()); inc[gb].clear(); }
};

vp vec;
vi tate[MAX_N];
vi yoko[MAX_N];
int n;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> n;
    vec.resize(n);
    rep(i,n){
        cin >> vec[i].fi >> vec[i].se;
        --vec[i].fi, --vec[i].se;
        tate[vec[i].fi].pb(vec[i].se);
        yoko[vec[i].se].pb(vec[i].fi);
    }
    UF uf(MAX_N);
    rep(i,MAX_N){
        if(tate[i].empty()) continue;
        srep(j,1,len(tate[i])){
            uf.unite(tate[i][0], tate[i][j]);
        }
    }
    ll ans = 0;
    rep(i,MAX_N){
        if(uf.inc[i].empty()) continue;
        set<int> st;
        ll res = 0;
        each(val,uf.inc[i]){
            each(num,yoko[val]){
                st.insert(num);
                res++;
            }
        }
        ans += (ll)st.size()*uf.inc[i].size() - res;
    }
    cout << ans << "\n";
    return 0;
}


Measured memory_bytes: 18292