#N,S,T,K=map(int, input().split())
#A=list(map(int, input().split()))

def make_divisors(n):
    lower_divisors , upper_divisors = [], []
    i = 1
    while i*i <= n:
        if n % i == 0:
            lower_divisors.append(i)
            if i != n // i:
                upper_divisors.append(n//i)
        i += 1
    return lower_divisors + upper_divisors[::-1]

T=int(input())
for _ in range(T):
  N,K=map(int, input().split())
  ans=-1
  for i in range(N,-1,-1):
    A=make_divisors(i)
    f=1
    for j in range(len(A)):
      if max(A[j],A[-1-j])<=K:
        f=-1
    if f==1:
      ans=i
      break
    if len(A)==2:
      break
  print(ans)