import sys
input = sys.stdin.readline

T = int(input())
for _ in range(T):
    L, R = map(int, input().split())
    if (R - L) % 4 != 0:
        if (R - L) // 4 % 2:
            print(0)
        else:
            print(1)
    else:
        if (R - L) // 4 % 2:
            print(L + R + 1)
        else:
            print(L + R)