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.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.StringTokenizer;

public class Main {
	
	static FastScanner fs = new FastScanner();

	public static void main(String[] args) {
		
		FastScanner fs = new FastScanner();
		int test = fs.nextInt();
		while(test-->0) {
			int a = fs.nextInt(), b = fs.nextInt();
//			int[] a = new int[n];
//			for(int i=0 ; i<n ; i++) {
//				a[i] = fs.nextInt();
//			}
			if(b/2+1>a) {
				System.out.println(b%(b/2+1));
			}else System.out.println(b%a);
		}
	}
	
	public static boolean check(int[] a) {
		for(int i=0 ; i<a.length ; i++) {
			if(a[i]!=i+1) return false;
		}
		return true;
	}
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	public static int[] readArray(int n){
		int[] a = new int[n];
		for(int i=0 ; i<n ; i++) {
			a[i] = fs.nextInt();
		}
        return a;
    }
	
	public static void printArray(int[] n){
        for(int e:n) {
        	System.out.print(e + " ");
        }
        System.out.println();
    }
	
	static void sort(int[] a) {
		ArrayList<Integer> l=new ArrayList<>();
		for (int i:a) l.add(i);
		Collections.sort(l);
		for (int i=0; i<a.length; i++) a[i]=l.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;
		}
		String[] readStringArray(int n) {
			String[] a=new String[n];
			for (int i=0; i<n; i++) a[i]=next();
			return a;
		}
		long nextLong() {
			return Long.parseLong(next());
		}
	}
	
	

}
