import java.io.*;

import java.util.*;

public class Main {
	//public static Node node[];
	public static int wall[],lazy[];
	public static void main(String[] args)throws IOException {
		// TODO Auto-generated method stub

// InputStreamReader isr=new InputStreamReader(System.in);
// OutputWriter out=new OutputWriter(System.out);
 //BufferedReader br=new BufferedReader(isr);


 Reader r=new Reader();
 int t=r.nextInt();
 for(int ii=1;ii<=t;ii++)
 {
 int n=r.nextInt();

 int q[][]=new int[n][2];
 int max=-1;
 for(int i=0;i<n;i++)
 {

	 q[i][0]=r.nextInt()-1;
	 q[i][1]=r.nextInt()-1;
	 max=Math.max(max,q[i][1]);





 }
 wall=new int[4*max];
 lazy=new int[4*max];

 for(int i=0;i<n;i++)
 {
	 modify(1,0,max-1,q[i][0],q[i][1],i+1);



 }

 pass(1,0,max-1);

 int c=0;int pos[]=new int[n+1];
 for(int i=0;i<max;i++)
	 if(wall[i]!=0 &&pos[wall[i]]==0)
	 {c++;pos[wall[i]]=1;}


System.out.println(c);
	}

	}

	public static void pass(int index,int l,int r)
	{
		if(l==r)
			return;

		int mid=(l+r)/2;

		if(lazy[index]!=0)
			shift(index,l,r);

		pass(index*2,l,mid);
		pass(index*2+1,mid+1,r);





	}
	public static void upd(int index,int l,int r,int poster)
	{
		if(l==r)
			{wall[l]=poster;return;}

		lazy[index]=poster;



	}
	public static void shift(int index,int l,int r)
	{

		int mid=(l+r)/2;

		upd(index*2,l,mid,lazy[index]);
		upd(index*2+1,mid+1,r,lazy[index]);

		lazy[index]=0;


	}
	public static void modify(int index,int l,int r,int x,int y,int poster)
{ //System.out.println(l+" "+r+" "+index+" "+pos);
		if(x<=l && y>=r)
		{
			upd(index,l,r,poster);
			return;


		}

		if(lazy[index]!=0)
			shift(index,l,r);

		int mid=(l+r)/2;

		if(y<=mid)
			modify(index*2,l,mid,x,y,poster);
		else if(x>mid)
			modify(index*2+1,mid+1,r,x,y,poster);
		else
		{
			modify(index*2,l,mid,x,mid,poster);
			modify(index*2+1,mid+1,r,mid+1,y,poster);
		}


}













}

//class Node{



//}
class Reader {
    final private int BUFFER_SIZE = 1 << 16;private DataInputStream din;private byte[] buffer;private int bufferPointer, bytesRead;
    public Reader(){din=new DataInputStream(System.in);buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;
    }public Reader(String file_name) throws IOException{din=new DataInputStream(new FileInputStream(file_name));buffer=new byte[BUFFER_SIZE];bufferPointer=bytesRead=0;
    }public String readLine() throws IOException{byte[] buf=new byte[64];int cnt=0,c;while((c=read())!=-1){if(c=='\n')break;buf[cnt++]=(byte)c;}return new String(buf,0,cnt);
    }public int nextInt() throws IOException{int ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;
    }public long nextLong() throws IOException{long ret=0;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c=read();do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(neg)return -ret;return ret;
    }public double nextDouble() throws IOException{double ret=0,div=1;byte c=read();while(c<=' ')c=read();boolean neg=(c=='-');if(neg)c = read();do {ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');if(c=='.')while((c=read())>='0'&&c<='9')ret+=(c-'0')/(div*=10);if(neg)return -ret;return ret;
    }private void fillBuffer() throws IOException{bytesRead=din.read(buffer,bufferPointer=0,BUFFER_SIZE);if(bytesRead==-1)buffer[0]=-1;
    }private byte read() throws IOException{if(bufferPointer==bytesRead)fillBuffer();return buffer[bufferPointer++];
    }public void close() throws IOException{if(din==null) return;din.close();}
}

class OutputWriter {
	private final PrintWriter writer;

	public OutputWriter(OutputStream outputStream) {
		writer = new PrintWriter(outputStream);
	}

	public OutputWriter(Writer writer) {
		this.writer = new PrintWriter(writer);
	}

	public void print(Object... objects) {
		for (int i = 0; i < objects.length; i++) {
			if (i != 0)
				writer.print(' ');
			writer.print(objects[i]);
		}
	}

	public void printLine(Object... objects) {
		print(objects);
		writer.println();
	}

	public void close() {
		writer.close();
	}
}