import java.io.BufferedReader
import java.io.InputStream
import java.io.InputStreamReader
import java.lang.AssertionError
import java.util.*
import kotlin.math.abs
import kotlin.math.max
import kotlin.math.min
import kotlin.math.sqrt

val MOD = 1_000_000_007


/**
 * a, bがマイナスでもうまいこと動く
 */
private inline fun floor_div(a: Long, b: Long): Long {
  val sign = java.lang.Long.signum(b)
  val x = a*sign
  val y = b*sign
  return if (x > 0) x/y else -((-x+y-1)/y)
}

private inline fun ceil_div(a: Long, b: Long): Long {
  val sign = java.lang.Long.signum(b)
  val x = a*sign
  val y = b*sign
  return if (x > 0) (x+y-1)/y else x/y
}

/**
 * x < a/b を満たす整数xの最大
 */
private inline fun div_lt(a: Long, b: Long) = ceil_div(a, b) - 1

/**
 * x <= a/b を満たす整数xの最大
 */
private inline fun div_le(a: Long, b: Long) = floor_div(a, b)

/**
 * x > a/b を満たす整数xの最小
 */
private inline fun div_gt(a: Long, b: Long) = floor_div(a, b) + 1

/**
 * x >= a/b を満たす整数xの最小
 */
private inline fun div_ge(a: Long, b: Long) = ceil_div(a, b)

/**
 * 単調増加
 * (l, h] 方式
 * @return マッチするものがなかったらmx
 */
inline fun findMin(mn: Long, mx: Long, f: (Long) -> Boolean): Long {
  var low = mn - 1
  var high = mx
  while(high - low > 1) {
    val m = (low + high) / 2
    if (f(m)) high = m
    else low = m
  }
  return high
}
class Solver(stream: InputStream, private val out: java.io.PrintWriter) {
  private val reader = BufferedReader(InputStreamReader(stream), 32768)

  fun solve() {
    val (L, R) = nal(2)
    val N = (R - L + 1).toInt()
    val free = BooleanArray(N){true}
//    val MAX = if (isDebug) 10L else 1_000_000L
    val MAX = 1_000_000L
    for (x in 2L .. MAX) {
      val d = x*x
      val a = div_ge(L, d)
      var y = a*d
//      debug{"x:$x a:$a y:$y"}
      while(y <= R) {
        free[(y - L).toInt()] = false
        y += d
      }
    }
//    debug(free)

    val inf = 2e18.toLong() + 100

    var x = MAX + 1
    while(x*x <= R) {
      val a = div_ge(L, x*x)
      val y = a*x*x
      if (y <= R) free[(y - L).toInt()] = false
      val b = a - 1
//      debug{"x:$x a:$a y:$y"}
      if (b == 0L) break
      x = findMin(x + 1, sqrt((inf/b).toDouble()).toLong()) { nx ->
        b*nx*nx >= L
      }
    }

    out.println(free.count { it })
  }













































  private val isDebug = try {
    // なんか本番でエラーでる
    System.getenv("MY_DEBUG") != null
  } catch (t: Throwable) {
    false
  }

  private var tokenizer: StringTokenizer? = null
  private fun next(): String {
    while (tokenizer == null || !tokenizer!!.hasMoreTokens()) {
      tokenizer = StringTokenizer(reader.readLine())
    }
    return tokenizer!!.nextToken()
  }

  private fun ni() = next().toInt()
  private fun nl() = next().toLong()
  private fun ns() = next()
  private fun na(n: Int, offset: Int = 0): IntArray {
    return IntArray(n) { ni() + offset }
  }
  private fun nal(n: Int, offset: Int = 0): LongArray {
    val res = LongArray(n)
    for (i in 0 until n) {
      res[i] = nl() + offset
    }
    return res
  }

  private fun na2(n: Int, offset: Int = 0): Array<IntArray> {
    val a  = Array(2){IntArray(n)}
    for (i in 0 until n) {
      for (e in a) {
        e[i] = ni() + offset
      }
    }
    return a
  }

  private inline fun debug(msg: () -> String) {
    if (isDebug) System.err.println(msg())
  }

  /**
   * コーナーケースでエラー出たりするので、debug(dp[1])のように添え字付きの場合はdebug{}をつかうこと
   */
  private inline fun debug(a: LongArray) {
    debug { a.joinToString(" ") }
  }

  private inline fun debug(a: IntArray) {
    debug { a.joinToString(" ") }
  }

  private inline fun debug(a: BooleanArray) {
    debug { toString(a) }
  }

  private inline fun toString(a: BooleanArray) = run{a.map { if (it) 1 else 0 }.joinToString("")}

  private inline fun debugDim(A: Array<LongArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }
  private inline fun debugDim(A: Array<IntArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }
  private inline fun debugDim(A: Array<BooleanArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }

  /**
   * 勝手にimport消されるのを防ぎたい
   */
  private fun hoge() {
    min(1, 2)
    max(1, 2)
    abs(-10)
  }

  private inline fun assert(b: Boolean) = run{if (!b) throw AssertionError()}
  private inline fun assert(b: Boolean, f: () -> String) = run{if (!b) throw AssertionError(f())}

  companion object {
    // TestRunnerから呼びたいので単純なmainじゃだめ
    fun main() {
      val out = java.io.PrintWriter(System.out)
      Solver(System.`in`, out).solve()
      out.flush()
    }
  }
}

/**
 * judgeから呼ばれる
 */
fun main() = Solver.main()