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.
/* package codechef; // don't place package name! */
/* ROHAN SHARMA */
import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class A {

    public static final Scanner sc = new Scanner(System.in);
    public static final int MOD = 1000000007;


    public static void main (String[] args) throws java.lang.Exception
    {
        int T = sc.nextInt();
        sc.nextLine();

        while (T-- > 0) {
            solve();
        }
    }


    public static void solve(){

        int l = sc.nextInt();
        int r = sc.nextInt();

        if(l > r /2){
            System.out.println(r % l);
        }else{
            System.out.println((r) % ((r / 2) + 1));
        }
    }


}