import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import log,gcd

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

def solve(L,R):
    if (L+R)%2:
        n = (L+R-1)//2-L+1
        res = n*(n+1)//2
        return res%2
    else:
        n = (L+R-2)//2-L+1
        res = n*(n+1)//2
        res %= 2
        if ((L+R)//2-L+1)%2:
            return (L+R)^res
        else:
            return res

for _ in range(int(input())):
    L,R = mi()
    print(solve(L,R))