#include<map>#include<set>#include<list>#include<cmath>#include<ctime>#include<queue>#include<stack>#include<cctype>#include<cstdio>#include<string>#include<vector>#include<cstdlib>#include<cstring>#include<iostream>#include<algorithm>using namespace std;struct node{int d,c;}a[10005];bool cmp(node a,node b){if(a.d!=b.d)return a.d<b.d;else return a.c<b.c;}int main(){int n;while(cin>>n && n){for(int i=0;i<n;i++)scanf("%d%d",&a[i].d,&a[i].c);sort(a,a+n,cmp);int cnt=0,min=999999;for(int i=0;i<n;i++){if(a[i].c<min){min=a[i].c;cnt++;}}printf("%dn",cnt);}return 0;}
