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.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class taska {
	public static void main(String[] args) {
		FastScanner in = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		int tt = in.nextInt();
		for (int tc = 0; tc < tt; tc++) {
			int l = in.nextInt(), r = in.nextInt();
			int i = l;
			int low = l, high = r;
			while (low <= high) {
				int mid = (low + high) / 2;
				if (2 * mid - 1 <= r) {
					i = mid;
					low = mid+1;
				} else {
					high = mid-1;
				}
			}
			int j = Math.min(2*i-1, r);
			out.println(j % i);
		}
		out.flush();
	}

	static class FastScanner {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer tok = new StringTokenizer("");
		String next() {
			while(!tok.hasMoreTokens()) {
				try {
					tok = new StringTokenizer(br.readLine());
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			return tok.nextToken();
		}
		int nextInt() {
			return Integer.parseInt(next());
		}
		long nextLong() {
			return Long.parseLong(next());
		}
		float nextFloat() {
			return Float.parseFloat(next());
		}
		double nextDouble() {
			return Double.parseDouble(next());
		}
	}
}
