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 jdk.jfr.SettingControl;

import java.io.*;
import java.util.*;

public class A {
	static class InputReader {
		BufferedReader reader;
		StringTokenizer tokenizer;
		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}
		String next() {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			return tokenizer.nextToken();
		}
		public int ni() {
			return Integer.parseInt(next());
		}
		public long nl() {
			return Long.parseLong(next());
		}
		public double nd() {
			return Double.parseDouble(next());
		}
		
		public int[] ra(int n ) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++) {
				a[i] = r.ni();
			}
			return a;
		}
	}
	
	public static void sort(int[] a) {
		List<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);
		}
	}
	
	public static void sortL(long[] a) {
		List<Long> l = new ArrayList<>();
		for (long i: a) {
			l.add(i);
		}
		Collections.sort(l);
		for (int i = 0; i < a.length; i++) {
			a[i] = l.get(i);
		}
	}
	
	static InputReader r = new InputReader(System.in);
	static PrintWriter pw = new PrintWriter(System.out);
	public static void main(String[] args) {
		int TT = r.ni();
		while (TT-- > 0) {
			long a = r.nl(), b = r.nl();
			pw.println(b % Math.max(a, (b + 2) / 2));
		}
		pw.close();
	}
}
