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.
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import java.util.*;


public class Main
{
	public static void main(String[] args) {
	    Scanner sc=new Scanner(System.in);
	    int t=sc.nextInt();
	    while(t--!=0)
	    {
	        long a=sc.nextLong();
	        long b=sc.nextLong();
	        a=Math.max(a,b);
	        b=Math.min(a,b);
	        long x=(a/2)+1;
	        //System.out.println(x);
	        if(b<=x)
	        {
	            System.out.println(a%(x));
	        }
	        else
	        {
	            
	            System.out.println(a%b);
	        }
	    }
	}
}
