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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Random;
import java.util.StringTokenizer;

public final class A {

    public static void main(String[] args) {
        final FastScanner fs = new FastScanner();
        final int t = fs.nextInt();
        final StringBuilder sb = new StringBuilder();
        for (int test = 0; test < t; test++) {
            final int a = fs.nextInt();
            final int b = fs.nextInt();
            int mod = Math.max(a, (b / 2) + 1);
            sb.append(b - mod).append('\n');
        }
        System.out.println(sb);
    }

    static final class Utils {
        private static class Shuffler {
            private static void shuffle(int[] x) {
                final Random r = new Random();

                for (int i = 0; i <= x.length - 2; i++) {
                    final int j = i + r.nextInt(x.length - i);
                    swap(x, i, j);
                }
            }

            private static void shuffle(long[] x) {
                final Random r = new Random();

                for (int i = 0; i <= x.length - 2; i++) {
                    final int j = i + r.nextInt(x.length - i);
                    swap(x, i, j);
                }
            }

            private static void swap(int[] x, int i, int j) {
                final int t = x[i];
                x[i] = x[j];
                x[j] = t;
            }

            private static void swap(long[] x, int i, int j) {
                final long t = x[i];
                x[i] = x[j];
                x[j] = t;
            }
        }

        public static void shuffleSort(int[] arr) {
            Shuffler.shuffle(arr);
            Arrays.sort(arr);
        }

        public static void shuffleSort(long[] arr) {
            Shuffler.shuffle(arr);
            Arrays.sort(arr);
        }

        private Utils() {}
    }

    static class FastScanner {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer("");

        private String next() {
            while (!st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    //noinspection CallToPrintStackTrace
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

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

        int[] nextIntArray(int n) {
            final int[] a = new int[n];
            for (int i = 0; i < n; i++) { a[i] = nextInt(); }
            return a;
        }

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