def solve(l, r):
    mi = 2 * l
    ma = l + r
    cnt = ma - mi + 1
    d = cnt % 8
    if d == 0 or d == 7 or d == 6:
        return 0
    elif d == 5:
        return ma ^ 1
    elif d == 4 or d == 3 or d == 2:
        return 1
    elif d == 1:
        return ma
    
    


def stupid(l, r):
    if l >= 20000:return
    ans = 0
    for i in range(l, r + 1):
        for j in range(i, r + 1):
            if i + j <= l + r:
                ans ^= i + j
    return ans


for _ in range(int(input())):
    l, r = map(int, input().split())
    print(solve(l, r))

exit()
import random
random.seed(0)
for _ in range(1000):
    l = random.randrange(1, 100)
    r = random.randrange(l, 100)
    assert solve(l, r) == stupid(l, r)