#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 1000000000000000001

int main(){
	
	int n;
	cin>>n;
	
	vector<int> a(n),b(n);
	vector<int> t;
	rep(i,n){
		cin>>a[i]>>b[i];
		t.push_back(a[i]);
		t.push_back(b[i]);
	}
	sort(t.begin(),t.end());
	t.erase(unique(t.begin(),t.end()),t.end());
	vector<vector<int>> E(t.size());
	rep(i,n){
		a[i]=lower_bound(t.begin(),t.end(),a[i])-t.begin();
		b[i]=lower_bound(t.begin(),t.end(),b[i])-t.begin();
		E[a[i]].push_back(b[i]);
	}
	
	vector<int> dp(t.size(),0);
	rep(i,t.size()){
		rep(j,E[i].size()){
			dp[E[i][j]] = max(dp[E[i][j]],dp[i]+1);
		}
		if(i!=t.size()-1)dp[i+1] = max(dp[i+1],dp[i]);
	}
	int ans =0;
	rep(i,t.size()){
		ans = max(ans,dp[i]);
	}
	cout<<n-ans<<endl;
	return 0;
}