import math as m
t = int(input())
for _ in range(t):
    n,x = map(int, input().split())
    a = list(map(int,input().split()))
    ans = [0]*1000001
    
    for ai in a:
        sq = int(m.sqrt(ai))
        for ii in range(1,sq+1,1):
            if(ai%ii):
                continue
            if(ii==ai//ii):
                ans[ii] += ai
            else:
                ans[ii] += ai
                ans[ai//ii] += ai
    
    sum = ans[x]
    sol = x
    for i in range(x,0,-1):
        if(ans[i]<=sum):
            sol=i
            sum=ans[i]
    print(sol)