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,math,io,os,time,itertools,collections
mod=10**9+7
sys.setrecursionlimit(10000)
i=sys.stdin.readline
p=sys.stdout.write
#use sys.stdout.write() (remember to convert to str b4 and concatenate "\n")
global start,end

#binary search
def isin(l,x):
    left=0
    right=len(l)-1
    if x<l[0]:
        return -1
    while left<=right:
        mid=left + (right -left)//2
        if l[mid]==x:
            return mid
        elif l[mid]<x:
            ans=mid
            left=mid+1
        else:
            right=mid-1
    return ans

#is palindrome or not
def ispal(l):
    n=len(l)
    for i in range(n//2+1):
        if l[i]!=l[n-i-1]:
            return False
    return True

#coordinate compression
def ccarray(l):
    d={l[k]:k for k in range(len(l))}
    m=sorted(d)
    return [d[m[k]] for k in range(len(l))]

#checks if prime or not
def is_prime(n):
    if n<=3:
        return n>1
    if n%2==0 or n%3==0:
        return False
    k=5
    while k**2<=n:
        if n%k==0 or n%(k+2)==0:
            return False
        k+=6
    return True

#sieve of eratosthenes
def sieve(n):
    prime=[True for k in range(n+1)]
    p=2
    while p*p<=n:
        if prime[p]==True:
            for k in range(p*p,n+1,p):
                prime[k]=False
        p+=1

def main():
    l,r=[int(k) for k in i().split()]
    z=r//2 +1
    l=int(max(l,z))
    ans=r%l
    p(str(ans)+"\n")

t=1
t=int(i())
start=time.perf_counter()
for _ in range(t):
    main()
end=time.perf_counter()
#print(end-start)