#include<bits/stdc++.h>
using namespace std;

template <typename T>
inline void read(T &x){
	x = 0;
	static char c;
	static bool f;
	c = getchar(), f = 0;
	while(c < '0' || c > '9'){ if(c == '-')f = 1; c = getchar(); }
	while('0' <= c && c <= '9')x = (x << 3) + (x << 1) + (c ^ 48), c = getchar();
	x = f ? -x : x;
}
template <typename T,typename ...Types>
inline void read(T &x,Types &...y){
	read(x);
	read(y...);
}

const int N = 5e5 + 10;
using pii = pair<int,int>;
priority_queue<int,vector<int>,greater<int>> a,b;
pii s[N];
int n;

int main(){
	read(n);
	for(int i = 1;i<=n;++i)read(s[i].first,s[i].second);
	sort(s+1,s+n+1);
	int ans = 0;
	for(int i = 1;i<=n;++i){
		pii p = s[i];
		int l = p.first, r = p.second;
		if(a.size() && a.top() < l)a.pop(),++ans,b.push(r);
		else if(b.size() && b.top() < r)a.push(b.top()),b.pop(),b.push(r);
		else a.push(r);
	}
	printf("%d",ans);
	return 0;
}