#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2")
#include <bits/stdc++.h>
#define INF 1000000001LL
#define LNF 1000000000000000001LL
#define MOD 1000000007LL
#define MAX 300005
#define long long long
#define all(x) x.begin(),x.end()
using namespace std;
int main()
{
	ios_base::sync_with_stdio(0); 
    cin.tie(0);

    int n;
    cin >> n;

    vector<pair<long,long>> arr(n);

    for(int i = 0; i<n; i++)
        cin >> arr[i].second >> arr[i].first;
    sort(all(arr));
    vector<long> lis;

    for(int i = 0; i<n; i++)
    {
        int ind = upper_bound(all(lis),arr[i].second)-lis.begin();
        if(ind == lis.size())
            lis.push_back(arr[i].first);
    }

    cout << n-lis.size() << endl;
    return 0;
}