#include<cstdio>
#include<algorithm>
using namespace std;
struct Activity {
    int start;
    int end;
};
bool cmp(Activity a, Activity b) {
    return a.end < b.end;//结束时间小的在左边的意思
}
int main()
{
    int m,n;
    scanf("%d",&m);
    while(m--)//m组
    {
        scanf("%d",&n);//n个活动
        Activity activities[10001];  // 使用结构体数组
        // 读取所有活动
        for(int i=0;i<n;i++)
        {
            scanf("%d%d",&activities[i].start, &activities[i].end);
        }
        // 按结束时间排序
        sort(activities, activities + n, cmp);
        int count = 0;
        int lasttime = -1;
        for(int i=0;i<n;i++)
        {
            if(lasttime < activities[i].start)
            {
                count++;
                lasttime = activities[i].end;
            }
        }
        printf("%d\n",count);
    }
    return 0;
}