import sys

def main():
    X, Y = map(int, sys.stdin.readline().split())
    if X == 0:
        X = 1  # Since R >=1 per problem constraints
    
    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):
        n = R
        valid = True
        res = 1
        while n > 1:
            p = spf[n]
            count_p = 0
            while n % p == 0:
                count_p += 1
                n = n // p
            mod4 = p % 4
            if mod4 == 3:
                if count_p % 2 != 0:
                    valid = False
                    break
            elif mod4 == 1:
                res *= (count_p + 1)
        if valid:
            current = res * 4
            if current > max_f:
                max_f = current
    print(max_f)

if __name__ == '__main__':
    main()