#mempi=dict()
mempi={1:0,2:1,3:2,4:2,5:3,6:3,7:4,8:4,9:4,10:4,11:5}
memP2=dict()
memPHI=dict()
P=[]
M=10000000
F=[0]*M
for i in range(2,M):
  if F[i]:
    continue
  P.append(i)
  for j in range(i*2,M,i):
    F[j]=1
X=[0]*M
X[1]=0
Z=75000
Y=[[0]*400 for i in range(Z)]
for m in range(Z):
  for n in range(400):
    if m==0:
      continue
    if n==0:
      Y[m][n]=m
      continue
    Y[m][n]=Y[m][n-1]-Y[m//P[n-1]][n-1]
for t in range(len(P)-1):
  for i in range(P[t],P[t+1]):
    X[i]=t+1
def P2(m,n,y):
  if memP2.get((m,n,y),-1)>=0:
    return memP2[(m,n,y)]
  i=0
  x=0
  while i<len(P):
    if P[i]*P[i]>m:
      break
    if y<P[i]:
      x+=pi(m//P[i])-pi(P[i])+1
    i+=1
  #memP2[(m,n,y)]=x
  return x

def PHI(m,n):
  if m<Z:
    return Y[m][n]
  if m==0:
    return 0
  if n==0:
    return m
  x=memPHI.get((m,n),-1)
  if x>=0:
    return x
  x=PHI(m,n-1)-PHI(m//P[n-1],n-1)
  #memPHI[(m,n)]=x
  return x

s=set()
def pi(m):
  if m<1:
    return 0
  if m<M:
    return X[m]
  #if mempi.get(m,-1)>=0:
  #  return mempi[m]
  x=int(m**(1/3))
  n=0
  y=0
  for i in range(x-3,x+3):
    if i*i*i>=m:
      y=i
      n=pi(y)
      break
  x=PHI(m,n)+n-1-P2(m,n,y)
  mempi[m]=x
  return x

L,R=map(int,input().split())
if L==R:
  print(pi(R)-pi(R-1))
  exit()
print(pi(R)-pi(L-1)+pi(2*R-1)-pi(2*L))