#!/usr/bin/env PyPy3

from collections import Counter, defaultdict, deque
import itertools
import re
import math
from functools import reduce
import operator
import bisect
from heapq import *
import functools
mod=998244353

import sys
input=sys.stdin.readline
t = int(input())
for _ in range(t):
    l,r = map(int,input().split())
    m = (r - l + 1) % 8
    if m == 0 or m == 6 or m == 7:
        print(0)
    elif m == 1:
        print(r + l)
    elif m == 2 or m == 3 or m == 4:
        print(1)
    else:
        print(1 ^ (r + l))