description: It is a simplified version of problem F2. The difference between them is the constraints (F1: k ≤ 2, F2: k ≤ 10).
  
  You are given an integer n. Find the minimum integer x such that x ≥ n and the number x is k-beautiful.
  
  A number is called k-beautiful if its decimal representation having no leading zeroes contains no more than k different digits. E.g. if k = 2, the numbers 3434443, 55550, 777 and 21 are k-beautiful whereas the numbers 120, 445435 and 998244353 are not.
  
  Input
  
  The first line contains one integer t (1 ≤ t ≤ 10^4) — the number of test cases. Then t test cases follow.
  
  Each test case consists of one line containing two integers n and k (1 ≤ n ≤ 10^9, 1 ≤ k ≤ 2).
  
  Output
  
  For each test case output on a separate line x — the minimum k-beautiful integer such that x ≥ n.
  
  Example
  
  Input
  
  
  4
  1 1
  221 2
  177890 2
  998244353 1
  
  
  Output
  
  
  1
  221
  181111
  999999999
solution: import java.io.*;
  import java.util.*;
  public class Solution {
  	public static void main(String[] args) throws IOException 
  	{ 
  		FastScanner f= new FastScanner(); 
  		int ttt=1;
  		ttt=f.nextInt();
  		PrintWriter out=new PrintWriter(System.out);
  		outer: for(int tt=0;tt<ttt;tt++) {
  			int n=f.nextInt();
  			int k=f.nextInt();
  			char[] l=Integer.toString(n).toCharArray();
  			HashSet<Character> h=new HashSet<>();
  			while(true) {
  				h.clear();
  				for (char c :l) h.add(c);
  				if (h.size() <= k) {
  					System.out.println(l);
  					continue outer;
  				}
  				h.clear();
  				int ptr = 0;
  				for (; ; ptr++)
  				{	
  //					System.out.println(l);
  //					System.out.println(ptr);
  					h.add(l[ptr]);
  					if (h.size()>k)
  					{
  						while (l[ptr]=='9')
  							ptr--;
  						l[ptr]++;
  						for (int i=ptr+1;i<l.length;i++)
  							l[i] = '0';
  						break;
  					}
  				}
  				
  			}
  		}
  		out.close();
  	} 
  	static void sort(int[] p) {
          ArrayList<Integer> q = new ArrayList<>();
          for (int i: p) q.add( i);
          Collections.sort(q);
          for (int i = 0; i < p.length; i++) p[i] = q.get(i);
      }
  	static class FastScanner {
  		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
  		StringTokenizer st=new StringTokenizer("");
  		String next() {
  			while (!st.hasMoreTokens())
  				try {
  					st=new StringTokenizer(br.readLine());
  				} catch (IOException e) {
  					e.printStackTrace();
  				}
  			return st.nextToken();
  		}
  		
  		int nextInt() {
  			return Integer.parseInt(next());
  		}
  		int[] readArray(int n) {
  			int[] a=new int[n];
  			for (int i=0; i<n; i++) a[i]=nextInt();
  			return a;
  		}
  		long nextLong() {
  			return Long.parseLong(next());
  		}
  		double nextDouble() {
  			return Double.parseDouble(next());
  		}
  		long[] readLongArray(int n) {
  			long[] a=new long[n];
  			for (int i=0; i<n; i++) a[i]=nextLong();
  			return a;
  		}
  	}
  }