• Source 
    1. 					/* package codechef; // don't place package name! */
    2. 					import java.util.*;
    3. 					import java.lang.*;
    4. 					import java.io.*;
    5.  
    6. 					/* Name of the class has to be "Main" only if the class is public. */
    7. 					class Hacker1
    8. 					{
    9. 						public static void main (String[] args) throws java.lang.Exception
    10. 						{
    11.  
    12. 							Scanner sc=new Scanner(System.in);
    13. 							int t=sc.nextInt();
    14. 							while(t--!=0) {
    15. 							String s1="";
    16. 							String a1="";
    17. 						String s=sc.next();
    18. 						int n=sc.nextInt();
    19. 						int count=0;
    20. 						ArrayList<Integer> list=new ArrayList<Integer>(n);
    21. 						for(int j=0;j<s.length();j++) {
    22. 							list.add((int)s.charAt(j)-48);
    23. 						}
    24.  
    25. 						Collections.sort(list);
    26.  
    27. 						int bb=0;
    28.  
    29. 							for(int i=0;i<s.length();i++) {	
    30.  
    31. 								if((s.charAt(i)-48)==list.get(bb)&&s.charAt(i)<=48+n) {
    32. 									bb++;
    33.  
    34. 									s1=s1+s.charAt(i);
    35.  
    36. 									count++;
    37. 								}
    38.  
    39. 								}
    40. 							for(int i=count;i<s.length();i++) {
    41. 								a1+=n;
    42. 							}
    43. 							String c=s1+a1;
    44.  
    45.  
    46. 							System.out.println(c);
    47. 											}
    48.  
    49. 					}
    50. 					}
    51. 					// &&s.charAt(i)<48+n
    52.