//n^2 solution (TLEd)

#include<bits/stdc++.h>
using namespace std;
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
#define memo(a,v) memset(a,v,sizeof(a))
#define pb push_back
#define all(a) a.begin(),a.end()
#define eps (1e-9)
#define inf (1<<29)
#define i64 long long
#define u64 unsigned i64
#define AIN(a,b,c) assert(a<=b && b<=c)
#define MAXN 100000
#define Y first
#define X second
typedef pair<int,i64> pii;

pii a[MAXN];
bool covered [MAXN];
inline bool isOverlapped (int i, int j){
    int x = max (a[i].X, a[j].X);
    int y = min (a[i].Y, a[j].Y);
    return y-x>=0;
}

int main(){
    int t, cnt, n, i, j;
    scanf("%d",&t);
    AIN(1,t,100);
    while(t--){
        scanf("%d",&n);
        AIN(1,n,MAXN);
        for(i = 0;i<n;i++){
            scanf("%d %d",&a[i].X,&a[i].Y);
            AIN(0,a[i].X,a[i].Y);
            AIN(a[i].X,a[i].Y,2000);
            covered[i] = 0;
        }
        sort(a,a+n);
        cnt=0;
        for(i = 0;i<n;i++){
            if(covered[i]) continue;
            covered [i] = 1;
            cnt++;
            for(j = 0;j<n;j++){
                if(covered[j]) continue;
                if (isOverlapped (i, j)){
                    covered [j] = 1;
                }
            }
        }
        printf ("%d\n", cnt);
    }
	return 0;
}