import collections,sys,math,functools,operator,itertools,bisect,heapq,decimal,string,time,random
#sys.setrecursionlimit(10**9)
#sys.set_int_max_str_digits(0)
#input = sys.stdin.readline
#n = int(input())
#alist = list(map(int,input().split()))
#alist = []
for i in range(int(input())):
    n,m = map(int,input().split())
    l,r = 0,10**9
    for _ in range(30):
        mid = (l+r)//2
        if mid * 4 >= n and mid*8 >= n+m:
            r = mid
        else:
            l = mid
    print(r)