import sys
readline=sys.stdin.readline

T=int(readline())
for _ in range(T):
    L,R=map(int,readline().split())
    L,R=2*L,L+R+1
    L+=(R-L)//8*8
    i=0
    ans=0
    for x in range(L,R):
        if i%4 in (0,1):
            ans^=x
        i+=1
    print(ans)