human
Give me a Python program to find the largest possible value of a mod b over all pairs (a, b) of integers for which r≥ a ≥ b ≥ l given the following:
PYTHON3 solution for "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.":
assistant
#Here is Python program to find the largest possible value of a mod b over all pairs (a, b) of integers for which r≥ a ≥ b ≥ l.
 def f(l, r):
    if l <= r // 2:
        return r % (r // 2 + 1)
    else:
        return r % l
    
n = int(input())
lst = []
for item in range(n):
    lst.append(f(*[int(item) for item in input().split()]))
print(*lst, sep='\n')