import sys

def main():
    X, Y = map(int, sys.stdin.readline().split())
    if X == 0:
        print(4)
        return

    max_r = Y
    spf = list(range(max_r + 1))
    for i in range(2, int(max_r**0.5) + 1):
        if spf[i] == i:
            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]
            count = 0
            while current % p == 0:
                count += 1
                current //= p
            if p % 4 == 3:
                if count % 2 != 0:
                    valid = False
                    break
            else:
                if p % 4 == 1:
                    product *= (count + 1)
        if valid:
            current_f = 4 * product
            if current_f > max_f:
                max_f = current_f
    print(max_f)

if __name__ == "__main__":
    main()