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 math
import sys
import collections
import bisect
import time
import random
import itertools
from collections import Counter,defaultdict
def get_ints():return map(int, sys.stdin.readline().strip().split())
def get_list():return list(map(int, sys.stdin.readline().strip().split()))
def get_string():return sys.stdin.readline().strip()
for t in range(int(input())):
    l,r=get_ints()
    if r==l:
        ans=0
        print(ans)
    elif l+1==r:print(1)
    else:
        ans=max((r-1)%r//2,r%(r//2+1))
        print(ans)