#include <bits/stdc++.h>
#include <bits/extc++.h>
#define int int64_t

using namespace std;
using namespace __gnu_pbds;

template<typename T>
using orset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    int n;
    cin >> n;
    vector<pair<int, int>> v(n);
    for(auto &i: v)
        cin >> i.first >> i.second;
    sort(v.begin(), v.end());
    orset<int> s;
    int ans = 0;
    for(int i = 0; i < n; i++){
        s.insert(v[i].second);
        if(s.upper_bound(v[i].second) != s.end())
            ans += s.size() - s.order_of_key(*s.upper_bound(v[i].second));
    }
    cout << '\n';
    for(int i = 0; i < n; i++)
        swap(v[i].first, v[i].second);
    sort(v.begin(), v.end());
    s.clear();
    int ans_new = 0;
    for(int i = 0; i < n; i++){
        s.insert(v[i].second);
        if(s.upper_bound(v[i].second) != s.end())
            ans_new += s.size() - s.order_of_key(*s.upper_bound(v[i].second));
    }
    cout << min(ans, ans_new);
}