import sys

def sieve_min_prime(max_n):
    min_prime = [0] * (max_n + 1)
    for i in range(2, max_n + 1):
        if min_prime[i] == 0:
            min_prime[i] = i
            j = i * i
            while j <= max_n:
                if min_prime[j] == 0:
                    min_prime[j] = i
                j += i
    return min_prime

def compute_f(R, min_prime):
    product = 1
    n = R
    while n > 1:
        p = min_prime[n]
        if p == 0:
            p = n
        count = 0
        while n % p == 0:
            count += 1
            n = n // p
        if p % 4 == 3:
            if count % 2 != 0:
                return 0
        else:
            if p != 2:
                product *= (count + 1)
    return product * 4

def main():
    X, Y = map(int, sys.stdin.readline().split())
    if X == 0:
        X = 1
    max_n = Y
    min_prime = sieve_min_prime(max_n)
    max_f = 0
    for R in range(X, Y + 1):
        current_f = compute_f(R, min_prime)
        if current_f > max_f:
            max_f = current_f
    print(max_f)

if __name__ == '__main__':
    main()