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.
/**
 * @author teenGraph
 * @Date 27 Aug 2021 01:43:41PM 
 * Noob level infinity
 * 
 * 
 * 
 * */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
import java.util.StringTokenizer;
import java.util.List;
import java.util.Collections;
import java.util.Map;
import java.util.HashMap;
import java.util.ArrayDeque;
public class Junk5 {
 	private static FastScanner fs=new FastScanner();
	// private static List<Integer> graph[];
	private static PrintWriter out = new PrintWriter(System.out);
	public static void main(String[] args) {		
		int t = fs.nextInt();
		while(t-->0)
		{
			int l = fs.nextInt();
			int r = fs.nextInt();
			int ans = (r/2)+1;
			if(ans>=l)
			{
				System.out.println(r%ans);
			}
			else System.out.println(r-l);
			
		}


	}
	// a%b = max;
	// 
	
	
	static final Random random=new Random();
	
	static void ruffleSort(int [] a) {
		int n=a.length;//shuffle, then sort 
		for (int i=0; i<n; i++) {
			int oi=random.nextInt(n); int temp=a[oi];
			a[oi]=a[i]; a[i]=temp;
		}
		Arrays.sort(a);
	}

	
	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());
		}
		int [] sort(int [] arr)
		{
			List<Integer> list = new ArrayList<>();
			for(int i : arr) list.add(i);	
		
			Collections.sort(list);
			int res[] = new int[arr.length];
			for(int i=0;i<arr.length;i++) res[i] = list.get(i);
			

			return res;
		}
		void debug(int a)
		{
			System.out.println("This is var "+a);
		}
	}
 
	
}