#include <bits/stdc++.h>

#include <atcoder/fenwicktree.hpp>
#include <atcoder/segtree.hpp>
#include <atcoder/modint.hpp>
#include <atcoder/dsu.hpp>
#include <atcoder/lazysegtree.hpp>

using namespace atcoder;
using namespace std;
using ll = long long;
using ull = unsigned long long;
template <class T>
using max_heap = priority_queue<T>;
template <class T>
using min_heap = priority_queue<T, vector<T>, greater<>>;
ll ll_min = numeric_limits<ll>::min();
ll ll_max = numeric_limits<ll>::max();
ll ALPHABET_N = 26;
// using mint = modint998244353;
#define rep(i, n) for (ll i = (ll)0; i < (ll)n; i++)
#define rep_(i, k, n) for (ll i = (ll)k; i < (ll)n; i++)
#define all(a) a.begin(), a.end()

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	ll n;
	cin >> n;
	fenwick_tree<ll> ft(1000010);
	vector<pair<ll, ll>> V(n);
	rep(i, n)
	{
		cin >> V[i].second >> V[i].first;
	}
	sort(all(V));
	ll ans = 0;
	for (auto [ri, li] : V)
	{
		li--;
		ans += ft.sum(li + 1, ri);
		ft.add(li, 1);
	}
	cout << ans << endl;
	return 0;
}