# https://yukicoder.me/problems/no/3622
 
def solve(L, R):
    k_l = 0
    while L >0:
        k_l += 1
        L //= 2

    k_r = 0
    while R > 0:
        k_r += 1
        R //= 2

    if k_l == k_r:
        if k_l == 0:
            return 0
        else:
            return -1
    ans = 1 << (k_r - 1)
    ans2 = (1 << (k_r - 1)) - 1
    return ans * ans2



def main():
    T = int(input())
    answers = []
    for _ in range(T):
        L, R= map(int, input().split())
        ans = solve(L, R)
        answers.append(ans)


    for ans in answers:
        print(ans)




if __name__ == "__main__":
    main()