def Eratosthenes(N): #N以下の素数のリストを返す
    #iが素数のときis_prime_list[i]=1，それ以外は0
    N+=1
    is_prime_list = [True]*N
    m = int(N**0.5)+1
    for i in range(3,m,2):
        if is_prime_list[i]:
            is_prime_list[i*i::2*i]=[False]*((N-i*i-1)//(2*i)+1)
    return [2] + [i for i in range(3,N,2) if is_prime_list[i]]

n = 10**7
r = [1]*(n+1)
r[0] = 0
for p in Eratosthenes(n):
    if p==2: continue
    for i in range(p,n+1,p):
        j = i//p
        c = 1
        while j%p==0:
            j //= p
            c += 1
        if p%4==1:
            r[i] *= c+1
        else:
            if c%2: r[i] = 0

x,y = map(int,input().split())
print(max(r[x:y+1])*4)