from sys import stdin, setrecursionlimit
input = stdin.readline
readline = stdin.readline
T=int(input())
for i in range(T):
  N,M=map(int, input().split())
  x=(N-2*M)//10
  ans=0
  for i in range(x-5,x+6):
    i=max(i,0)
    a,b=N-2*i,M+4*i 
    ans=max(ans,min(a//4,b//2))
  print(ans*3)