import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


// floor(sqrt(a))
long floorSqrt(long a) {
  import core.bitop : bsr;
  import std.algorithm : min;
  long b = a, x = 0, y = 0;
  for (int e = bsr(a) & ~1; e >= 0; e -= 2) {
    x <<= 1;
    y <<= 1;
    if (b >= (y | 1) << e) {
      b -= (y | 1) << e;
      x |= 1;
      y += 2;
    }
  }
  return x;
}


enum LIM = 10^^6;
int[] lpf;

void main() {
  lpf = iota(LIM).array;
  foreach (p; 2 .. LIM) {
    if (lpf[p] == p) {
      for (int n = 2 * p; n < LIM; n += p) {
        chmin(lpf[n], p);
      }
    }
  }
  
  try {
    for (; ; ) {
      const L = readLong();
      const R = readLong();
      
      const len = cast(int)(R - L + 1);
      auto sq = new bool[len];
      auto val = new long[len];
      foreach (i; 0 .. len) {
        val[i] = L + i;
      }
      
      foreach (p; 2 .. LIM) {
        if (lpf[p] == p) {
          for (long x = (L + p - 1) / p * p; x <= R; x += p) {
            const i = cast(int)(x - L);
            val[i] /= p;
            for (; val[i] % p == 0; val[i] /= p) {
              sq[i] = true;
            }
          }
        }
      }
      
      foreach (i; 0 .. len) {
        if (val[i] >= 1L * LIM * LIM) {
          const y = floorSqrt(val[i]);
          if (val[i] == y * y) {
            sq[i] = true;
          }
        }
      }
      
      const ans = cast(int)(sq.count(false));
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}