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

public class test {

    static long mod = 1000000007;
    static long inf = Long.MAX_VALUE;

    public static void solve(long l, long r) {
        long max = r % l;
        long rhalf = r / 2 + 1;
        if(rhalf >= l) {
            max = Math.max(max, r % rhalf);
        }
        long ldouble = l * 2 -1;
        if(ldouble <= r) {
            max = Math.max(max, ldouble % l);
        }
        System.out.println(max);
    }
    
/*
input:
4
1 1
999999999 1000000000
8 26
1 999999999


output:
0
1
12
499999999


*/

    public static void main(String[] args) {
        FastReader sc = new FastReader();
        int t = sc.nextInt();
        while(t-- > 0) {
            long l = sc.nextLong();
            long r = sc.nextLong();
            // solve
            solve(l, r);
        }
    }

     
	public static void sort(long[] a) {
		ArrayList<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);
	}

    public static int maxIndex(long[] arr) {
        long max = Long.MIN_VALUE;
        int index = 0;
        int n = arr.length;
        for(int i = 0; i < n; i++) {
            if(arr[i] > max) {
                index = i;
                max = arr[i];
            }
        }
        return index;
    }

    public static int minIndex(long[] arr) {
        long min = Long.MAX_VALUE;
        int index = 0;
        int n = arr.length;
        for(int i = 0; i < n; i++) {
            if(arr[i] < min) {
                index = i;
                min = arr[i];
            }
        }
        return index;
    }

    public static void debugArray(long[] arr) {
        for(int i = 0; i < arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
        System.out.println();
    } 

    public static void debugArrayList(ArrayList<Long> arr) {
        for(Long i : arr) {
            System.out.print(i + " ");
        }
        System.out.println();
    }

    public static long gcd(long a, long b) {
        if(b == 0) {
            return a;
        }
        else {
            return gcd(b, a % b);
        }
    }
 
    public static long LCM(long a, long b) {
        return Math.abs(a*b) / gcd(a, b);
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;
    
        public FastReader() {
            br=new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while(st == null || !st.hasMoreElements()) {
                try {
                    st=new StringTokenizer(br.readLine());
                }
                catch(IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        String nextLine() {
            String str="";
            try {
                str=br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        long[] readArray(int n) {
            long[] a = new long[n];
            for(int i = 0; i < n ; i++) {
                a[i] = nextLong();
            }
            return a;
        }
    }
}