import sys
#input = sys.stdin.readline
input = sys.stdin.buffer.readline #文字列はダメ
#sys.setrecursionlimit(1000000)
#import bisect
#import itertools
#import random
#from heapq import heapify, heappop, heappush
#from collections import defaultdict 
#from collections import deque
#import copy
#import math
#from functools import lru_cache
#@lru_cache(maxsize=None)
#MOD = pow(10,9) + 7
#MOD = 998244353
#dx = [1,0,-1,0]
#dy = [0,1,0,-1]
#dx8 = [1,1,0,-1,-1,-1,0,1]
#dy8 = [0,1,1,1,0,-1,-1,-1]

##x以下の排他的論理和
#def f(x):
#    K = x.bit_length()
#    ret = 0
#    base = 1
#    for k in range(K+1):
#        loop = (x//(base*2)) * base % 2
#        amari = max(0, (x%(base*2) - base +1)) % 2
#        #print(loop,amari)
#        ret += ((loop + amari) %2) * base
#        base *= 2
#    return ret


def main():
    T = int(input())
    for _ in range(T):
        L,R = map(int,input().split())
        start = 2*L
        end = L+R
        #偶数^(偶数+1)=1となる組の数が以下
        num = ((end - start + 1)//4)
        #残り
        nokori = 0
        if (end - start)%4 == 3:
            pass
        elif (end - start)%4 == 0:
            nokori ^= end
        elif (end - start)%4 == 1:
            nokori ^= end-1
            nokori ^= end
        else:
            nokori ^= end-2
            nokori ^= end-1
        ans = nokori^(num%2)
        print(ans)

                
if __name__ == '__main__':
    main()