#include <bits/stdc++.h>
using namespace std;
struct Fast {
    Fast() {
        std::cin.tie(0);
        ios::sync_with_stdio(false);
        cout.precision(20);
    }
} fast;

/* define */
#define FOR(I, X, Y) for (long long(I) = (X); (I) < (Y); (I)++)
#define REP(I, X, Y) for (long long(I) = (Y)-1; (I) >= (X); (I)--)
#define ALL(X) (X).begin(), (X).end()
#define pb push_back
#define COUNT(V, X)                           \
    (upper_bound((V).begin(), (V).end(), X) - \
     lower_bound((V).begin(), (V).end(), X))
#define debug(x) cerr << #x << ':' << x << endl;
#define DEBUG(v)                             \
    {                                        \
        cerr << #v << ':';                   \
        for (auto xv : v) cerr << xv << ' '; \
        cerr << endl;                        \
    }
#define Yes(X) cout << (X ? "Yes" : "No") << endl;
#define YES(X) cout << (X ? "YES" : "NO") << endl;
#define ctoi(C) (C - '0')
#define pow2(x) ((long long)((long long)1 << x))

/* alias */
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vii = vector<vector<int>>;
using vl = vector<long long>;
using vll = vector<vector<long long>>;
using pi = pair<int, int>;
using pl = pair<long long, long long>;
template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using minPQ = priority_queue<T, vector<T>, greater<T>>;

/* const */
const long long dx[] = {1, 0, -1, 0};
const long long dy[] = {0, 1, 0, -1};
const long long dx8[] = {1, 1, 0, -1, -1, -1, 0, 1};
const long long dy8[] = {0, 1, 1, 1, 0, -1, -1, -1};
const long long dx9[] = {1, 1, 0, -1, -1, -1, 0, 1, 0};
const long long dy9[] = {0, 1, 1, 1, 0, -1, -1, -1, 0};
const int INF = 1000000007;
const long long LINF = 1000000000000000007;

/* func */
template <typename T1, typename T2>
inline bool chmin(T1 &a, const T2 &b) {
    if (a > b) a = b;
    return a > b;
}
template <typename T1, typename T2>
inline bool chmax(T1 &a, const T2 &b) {
    if (a < b) a = b;
    return a < b;
}
long long max(long long x, int y) {
    return max(x, (long long)y);
}
long long max(int x, long long y) {
    return max((long long)x, y);
}
long long min(long long x, int y) {
    return min(x, (long long)y);
}
long long min(int x, long long y) {
    return min((long long)x, y);
}

/* library */

struct UnionFind {
    vector<long long> data;

    UnionFind(long long N) : data(vector<long long>(N, -1)) {
    }

    long long root(long long x) {
        if (data[x] < 0)
            return x;
        else
            return data[x] = root(data[x]);
    }

    bool same(long long x, long long y) {
        return root(x) == root(y);
    }

    void unite(long long x, long long y) {
        if (!same(x, y)) {
            x = root(x);
            y = root(y);
            if (data[x] < data[y]) {
                data[x] += data[y];
                data[y] = x;
            } else {
                data[y] += data[x];
                data[x] = y;
            }
        }
        return;
    }

    long long getsize(long long x) {
        return -data[root(x)];
    }

    vector<long long> parents() {
        set<long long> s;
        vector<long long> ans;
        for (int i = 0; i < data.size(); i++) {
            s.insert(root(i));
        }
        for (set<long long>::iterator itr = s.begin(); itr != s.end(); itr++) {
            ans.push_back(*itr);
        }
        return ans;
    }
};

/* main */

signed main() {
    ll N;
    cin >> N;
    vector<pl> v;
    FOR(i, 0, N) {
        ll x, y;
        cin >> x >> y;
        v.push_back(make_pair(x, y));
    }
    if (N <= 2) {
        cout << 0 << endl;
        return 0;
    }
    sort(ALL(v));
    UnionFind UF(100001);
    FOR(i, 0, v.size() - 1) {
        if (v[i].first == v[i + 1].first) {
            UF.unite(v[i].second, v[i + 1].second);
        }
    }
    set<int> s;
    map<int, vector<pl>> m;
    FOR(i, 0, N) {
        m[UF.root(v[i].second)].push_back(v[i]);
        s.insert(UF.root(v[i].second));
    }
    ll ans = 0;
    for (auto p : s) {
        set<int> fir;
        set<int> sec;
        FOR(i, 0, m[p].size()) {
            fir.insert(m[p][i].first);
            sec.insert(m[p][i].second);
        }
        if (fir.size() == m[p].size()) continue;
        ans += fir.size() * sec.size() - m[p].size();
    }
    cout << ans << endl;
}

Measured memory_bytes: 8816