import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.math.*;

/*
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 * and open the template in the editor.
 */


/**
 *
 * @author jakab4
 */
public class Most {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws IOException {
      //  BufferedReader r = new BufferedReader(new FileReader(new File("C:\\Users\\jakab4\\Documents\\NetBeansProjects\\Most\\src\\vstup.txt")));  
       BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        int pocet = Integer.valueOf(r.readLine());    
        for(int i=0; i< pocet; i++)
        {
           int vstup = Integer.valueOf(r.readLine());
           int [][] voda = new int[vstup][2];
           StringTokenizer token;
           for(int j=0; j<vstup;j++)
           {
               token = new StringTokenizer(r.readLine()," ");
               voda[j][0] = Integer.valueOf(token.nextToken());
               voda[j][1] = Integer.valueOf(token.nextToken());        
           
        }
           int min = 1000000000;
           int hodnota = 0;
           for(int m=0; m < voda.length;m++)
           {
               for(int n=0; n < voda.length; n++)
               {
                 if(voda[n][1]-voda[m][0] < 0) hodnota = Math.abs(m-n)-1;
                 else hodnota = Math.abs(voda[m][0]-voda[n][1])+Math.abs(m-n);
                 if(hodnota < min) min = hodnota;
               } 
           }
        System.out.println("K prechodu reky je treba " +(min) +" pontonu." );
    }
    
}
}