You are given two integers l and r, l≤ r. Find the largest possible value of a mod b over all pairs (a, b) of integers for which r≥ a ≥ b ≥ l.

As a reminder, a mod b is a remainder we get when dividing a by b. For example, 26 mod 8 = 2.

Input

Each test contains multiple test cases.

The first line contains one positive integer t (1≤ t≤ 10^4), denoting the number of test cases. Description of the test cases follows.

The only line of each test case contains two integers l, r (1≤ l ≤ r ≤ 10^9).

Output

For every test case, output the largest possible value of a mod b over all pairs (a, b) of integers for which r≥ a ≥ b ≥ l.

Example

Input


4
1 1
999999999 1000000000
8 26
1 999999999


Output


0
1
12
499999999

Note

In the first test case, the only allowed pair is (a, b) = (1, 1), for which a mod b = 1 mod 1 = 0.

In the second test case, the optimal choice is pair (a, b) = (1000000000, 999999999), for which a mod b = 1.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class A_The_Miracle_and_the_Sleeper {

     static Scanner in=new Scanner();
    
  static PrintWriter out=new PrintWriter( new OutputStreamWriter(System.out) );
   
  static int testCases;
  
  static long a,b;
  
   static void solve(){
       
       if( a==b ){
           
           out.println(0);
           out.flush();
           
       }else if( Math.abs(a-b)==1 ){
           
           out.println(1);
           out.flush();
           
       }else if( a>b/2 ){
           
           out.println( b%a );
           out.flush();
           
       }else{
           
           out.println( ( b%((b/2)+1  ) ) );
           out.flush();
           
       }
       
   }
    
    public static void main(String[] amit) throws IOException {
        
        testCases=in.nextInt();
        
        for(int t=0;t<testCases;t++){
            
            a=in.nextLong();
            b=in.nextLong();
            
            solve();
            
        }
        
        in.close();
        
    }
    
     static class Scanner{
        
        BufferedReader in;
        StringTokenizer st;

        public Scanner() {
        
            in=new BufferedReader( new InputStreamReader(System.in) );
            
        }
        
        String next() throws IOException{
            
            while(st==null || !st.hasMoreElements()){
                
                st=new StringTokenizer(in.readLine());
                
            }
            
            return st.nextToken();
            
        }
        
        int nextInt() throws IOException{
            
            return Integer.parseInt(next());
            
        }
        
        long nextLong() throws IOException{
            
            return Long.parseLong(next());
            
        }
        
        String nextLine() throws IOException{
            
            return in.readLine();
            
        }
        
        char nextChar() throws IOException{
            
            return next().charAt(0);
            
        }
        
        double nextDouble() throws IOException{
            
            return Double.parseDouble(next());
            
        }
        
        float nextFloat() throws IOException{
            
            return Float.parseFloat(next());
            
        }
        
        boolean nextBoolean() throws IOException{
            
            return Boolean.parseBoolean(next());
            
        }
        
        void close() throws IOException{
            
            in.close();
            
        }
        
    }
    
}
/*

4
1 1
999999999 1000000000
8 26
1 999999999


*/