#include <bits/stdc++.h>
using namespace std;
using LL = long long;
using LD = long double;
using PII = pair<int, int>;
using PLI = pair<long long, int>;
using PLL = pair<long long, long long>;
using TI = tuple<int, int, int>;
template<class A, class B> ostream& operator <<(ostream& out, const pair<A, B> &p) {
    return out << "(" << p.first << ", " << p.second << ")";
}
template<class A, class B, class C> ostream& operator <<(ostream& out, const tuple<A, B, C> &t) {
    return out << "(" << get<0>(t) << ", " << get<1>(t) << ", " << get<2>(t) << ")";
}
template <typename T, size_t N>
ostream& operator <<(ostream& out, const array<T, N>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const vector<T>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const deque<T>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const set<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator <<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& p : a) { out << (first ? "" : ", "); out << p.first << ":" << p.second; first = 0;} out << "}";
  return out;
}
template<class T> inline void YES(T condition) { 
    if(condition) cout << "YES" << endl;
    else cout << "NO" << endl;
}
template<class T> inline void Yes(T condition) {
    if(condition) cout << "Yes" << endl;
    else cout << "No" << endl;
}
template<class T> T gcd(T a, T b) {
    while (b) {
        T tmp = b;
        b = a % b;
        a = tmp;
    }
    return a;
}
template<class T> T lcm(T a, T b){
    return a / gcd(a, b) * b;
}

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

long long qpow(long long a, long long b, int MOD) {
    if (b == 0) return 1;
    long long res = 1;
    while (b) {
        if (b & 1) res = (res * a) % MOD;
        a = (a * a) % MOD;
        b >>= 1;
    }
    return res;
}

const int MOD = 1e9 + 7;
const int maxn = 2e6;
int fac[maxn + 5];
int invfac[maxn + 5];
void init() {
    fac[0] = 1;
    for (int i = 1; i <= maxn; i++) fac[i] = 1LL * fac[i - 1] * i % MOD;
    invfac[maxn] = (int)(qpow(fac[maxn], MOD - 2, MOD));
    for (int i = maxn - 1; i >= 0; i--) invfac[i] = 1LL * invfac[i + 1] * (i + 1) % MOD;
}
int C(int n, int k) {
    assert(0 <= k && n >= k);
    int tmp = (int)(1LL * invfac[k] * invfac[n - k] % MOD);
    return (int)(1LL * fac[n] * tmp % MOD);
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;
    vector<TI> a(n);
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        a[i] = make_tuple(i, x, y);
    }
    vector<int> fa(n);
    iota(fa.begin(), fa.end(), 0);
    vector<int> sz(n, 1);
    function<int(int)> Find = [&](const int x) {
        return x == fa[x] ? x : Find(fa[x]);
    };
    function<bool(int, int)> Union = [&](const int x, const int y) {
        int rootx = Find(x), rooty = Find(y);
        if (rootx == rooty) return false;
        if (sz[rootx] > sz[rooty]) swap(rootx, rooty);
        fa[rootx] = rooty;
        sz[rooty] += sz[rootx];
        return true;
    };
    
    // Union by same x
    sort(a.begin(), a.end(), [&](const TI& t1, const TI& t2) { return get<1>(t1) < get<1>(t2); });
    for (int i = 0, j = i; i < n; i = j) {
        for (j = i + 1; j < n && get<1>(a[i]) == get<1>(a[j]); j++) {
            Union(get<0>(a[i]), get<0>(a[j]));
        }
    }

    // Union by same y
    sort(a.begin(), a.end(), [&](const TI& t1, const TI& t2) { return get<2>(t1) < get<2>(t2); });
    for (int i = 0, j = i; i < n; i = j) {
        for (j = i + 1; j < n && get<2>(a[i]) == get<2>(a[j]); j++) {
            Union(get<0>(a[i]), get<0>(a[j]));
        }
    }
    vector<set<int>> X(n), Y(n);
    for (int i = 0; i < n; i++) {
        int r = Find(get<0>(a[i]));
        X[r].insert(get<1>(a[i]));
        Y[r].insert(get<2>(a[i]));
    }
    // trace(X);
    // trace(Y);
    // trace(sz);
    LL res = 0;
    for (int i = 0; i < n; i++) {
        if (i != Find(i)) continue;
        res += 1LL * (int)X[i].size() * (int)Y[i].size() - sz[i];
    }
    cout << res << '\n';



    return 0;
}


Measured memory_bytes: 16256