#include <iostream>
#include <stdio.h>
#define N 100
using namespace std;
struct node{
int begin;
int end;
} a[N+10];
int
cmp(node a, node b){
return (a.end<=b.end);//&&a.begin<b.begin);
}
int
main()
{
int n, t, k, ans;
while(cin>>n, n){
for(int i=0; i<n; i++)
cin>>a[i].begin>>a[i].end;;
sort(a, a+n, cmp);
k=0,ans=1;
for(int i=1; i<n; i++){
if(a[i].begin>=a[k].end){
ans++;
k=i;
}
}
cout<<ans<<endl;
}
return 0;
}
转载于:https://my.oschina.net/dianpaopao/blog/93332