t=int(input())
for _ in range(t):
    n,m=map(int,input().split())
    
    ng,ok=0,10**18
    while abs(ng-ok)>1:
        mid=(ok+ng)//2
        if n+m<=mid*8 and (n+3)//4<=mid:ok=mid
        else:ng=mid
    
    print(ok)