#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

void Solve() 
{
    int n; cin >> n;
    
    vector <pair<int, int>> a(n);
    for (auto &x : a){
        cin >> x.second >> x.first;
    }
    
    sort(a.begin(), a.end());
    vector <int> dp(n, 0);
    vector <int> pdp(n, 0);
    for (int i = 0; i < n; i++){
        // find how good x.second is 
        if (a[i].second < a[0].first){
            dp[i] = 1;
            pdp[i] = 1;
            if (i != 0) pdp[i] = max(pdp[i], pdp[i - 1]);
            continue;
        }
        
        int l = 0, r = n;
        while (l != r){
            int mid = (l + r + 1) / 2;
            
            if (a[i].second >= a[mid].first){
                l = mid;
            } else {
                r = mid - 1;
            }
        }
        
        dp[i] = 1 + pdp[l];
        pdp[i] = max(pdp[i - 1], dp[i]);
    }
    
    int ans = n - pdp[n - 1];
    cout << ans << "\n";
}

int32_t main() 
{
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    // freopen("in",  "r", stdin);
    // freopen("out", "w", stdout);
    
  //  cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    return 0;
}