import math, copy,sys
L,R = map(int,input().split())
if R == 1:
    print(1)
    sys.exit()
# 素数リスト作成
def seachPrimeNum(N):
    max = int(N**0.5)
    seachList = [i for i in range(2,N+1)]
    primeNum = []
    while seachList[0] <= max:
        primeNum.append(seachList[0])
        tmp = seachList[0]
        seachList = [i for i in seachList if i % tmp != 0]
    primeNum.extend(seachList)
    return primeNum

PL = seachPrimeNum(math.ceil(pow(R,1/3)))
AL = set(range(L,R+1))
for p in PL:
    p2 = p*p 
    for i in range(L//p2,R//p2+1):
        if i*p2 in AL:
            AL.remove(i*p2)
def check(x,y):
    return x >= y*y
AL2 = copy.copy(AL)
for a in AL2:
    lb = 0
    ub = R
    while ub - lb > 1:
        mid = (ub + lb) //2
        if check(a,mid):
            lb = mid
        else:
            ub = mid
    if a == lb * lb:
        AL.remove(a)
print(len(AL))