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 sys
AAA = """4
1 1
999999999 1000000000
8 26
1 999999999"""

first = True
# for line in AAA.splitlines():
for line in sys.stdin.readlines():
    if first:
        first = False
        continue
    l, r = map(int, line.split())

    max_mod = 0
    ma, mb = 0, 0
    b = max((r + 1) // 2, l)
    g = min(b + b - 1, r)
    print(g % b)
    # for b in range(l, r + 1):
    # for a in range(b, r + 1):
    #     if a % b >= max_mod:
    #         max_mod = a % b
    #         ma, mb = a, b
    # print(g)
    # print(g == ma)
    # print(max_mod)
    # print(ma, mb)
    # print()
