from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

def answer():
    
    x,y = map(int,input().split())
    for i in range(y,61):
        if (x>>i)&1:
            continue
        else:
            break
    if i==y:
        print(0)
        return
    print(pow(2,i)-1)
for _ in range(int(input())):
    answer()