#include <stdio.h>
#include <algorithm>
using namespace std;
struct act{
    int start;
    int end;
};
bool cmp(act a1,act a2){
    return a1.end<a2.end;
}
int main(){
    int m;
    scanf("%d",&m);
    while(m--){
        int n,i=0,cnt=0;
        act a[10001];
        scanf("%d",&n);
        while(i<n){
            scanf("%d%d",&a[i].start,&a[i].end);
            i++;
        }
        sort(a,a+n,cmp);
        int end=-1;
        for(i=0;i<n;i++){
            if(a[i].start>end){
                cnt++;
                end=a[i].end;
            }
        }
        printf("%d\n",cnt);
    }
    return 0;
}