import sys
import array

def main():
    X, Y = map(int, sys.stdin.readline().split())
    if X == 0:
        X = 1  # According to problem statement, X >=1
    
    # Sieve of smallest prime factors up to Y
    max_R = Y
    spf = array.array('I', (i for i in range(max_R + 1)))
    
    for i in range(2, int(max_R**0.5) + 1):
        if spf[i] == i:  # i is a prime
            for j in range(i * i, max_R + 1, i):
                if spf[j] == j:
                    spf[j] = i
    
    max_f = 0
    for R in range(X, Y + 1):
        current = R
        valid = True
        product = 1
        while current > 1:
            p = spf[current]
            if p % 4 == 3:
                count_p = 0
                while current % p == 0:
                    count_p += 1
                    current = current // p
                if count_p % 2 != 0:
                    valid = False
                    break
            else:
                count_p = 0
                while current % p == 0:
                    count_p += 1
                    current = current // p
                if p != 2:
                    product *= (count_p + 1)
        if valid:
            current_f = 4 * product
            if current_f > max_f:
                max_f = current_f
    print(max_f)

if __name__ == '__main__':
    main()