#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef long double ld;
#define sz(c) ((ll)(c).size())
#define ALL(x) x.begin(),x.end()
#define rep(i,a,b) for(int i=a;i<b;i++)
const long long inf=1e14;
int main() {
int n;cin>>n;
vector<pair<int,int>>P(n);
int c=-1;
rep(i,0,n){
	int r,R;cin>>r>>R;
	P[i]={R,r};
}
sort(ALL(P));
int ans=0;
rep(i,0,n){
	if(c<=P[i].second){ans++;c=P[i].first;}
}
cout<<n-ans;
}