def sieve(n):
    spf = list(range(n + 1))
    for i in range(2, int(n**0.5) + 1):
        if spf[i] == i:  # i is a prime
            for j in range(i * i, n + 1, i):
                if spf[j] == j:
                    spf[j] = i
    return spf

def main():
    import sys
    X, Y = map(int, sys.stdin.readline().split())
    max_f = 0
    spf = sieve(Y)
    for R in range(X, Y + 1):
        current_R = R
        valid = True
        product = 1
        p_count = {}
        while current_R > 1:
            p = spf[current_R]
            count = 0
            while current_R % p == 0:
                count += 1
                current_R //= p
            if p % 4 == 3:
                if count % 2 != 0:
                    valid = False
                    break
            elif p % 4 == 1:
                product *= (count + 1)
        if valid:
            current_f = 4 * product
        else:
            current_f = 0
        if current_f > max_f:
            max_f = current_f
    print(max_f)

if __name__ == '__main__':
    main()