A number is called almost prime if it has exactly two distinct prime divisors. For example, numbers 6, 18, 24 are almost prime, while 4, 8, 9, 42 are not. Find the amount of almost prime numbers which are between 1 and n, inclusive.

Input

Input contains one integer number n (1 ≤ n ≤ 3000).

Output

Output the amount of almost prime numbers between 1 and n, inclusive.

Examples

Input

10


Output

2


Input

21


Output

8
#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int a[430] = {
      2,    3,    5,    7,    11,   13,   17,   19,   23,   29,   31,   37,
      41,   43,   47,   53,   59,   61,   67,   71,   73,   79,   83,   89,
      97,   101,  103,  107,  109,  113,  127,  131,  137,  139,  149,  151,
      157,  163,  167,  173,  179,  181,  191,  193,  197,  199,  211,  223,
      227,  229,  233,  239,  241,  251,  257,  263,  269,  271,  277,  281,
      283,  293,  307,  311,  313,  317,  331,  337,  347,  349,  353,  359,
      367,  373,  379,  383,  389,  397,  401,  409,  419,  421,  431,  433,
      439,  443,  449,  457,  461,  463,  467,  479,  487,  491,  499,  503,
      509,  521,  523,  541,  547,  557,  563,  569,  571,  577,  587,  593,
      599,  601,  607,  613,  617,  619,  631,  641,  643,  647,  653,  659,
      661,  673,  677,  683,  691,  701,  709,  719,  727,  733,  739,  743,
      751,  757,  761,  769,  773,  787,  797,  809,  811,  821,  823,  827,
      829,  839,  853,  857,  859,  863,  877,  881,  883,  887,  907,  911,
      919,  929,  937,  941,  947,  953,  967,  971,  977,  983,  991,  997,
      1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069,
      1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163,
      1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249,
      1259, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321,
      1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439,
      1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511,
      1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601,
      1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667, 1669, 1693,
      1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783,
      1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877,
      1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987,
      1993, 1997, 1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069,
      2081, 2083, 2087, 2089, 2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143,
      2153, 2161, 2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243, 2251, 2267,
      2269, 2273, 2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339, 2341, 2347,
      2351, 2357, 2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411, 2417, 2423,
      2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531, 2539, 2543,
      2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617, 2621, 2633, 2647, 2657,
      2659, 2663, 2671, 2677, 2683, 2687, 2689, 2693, 2699, 2707, 2711, 2713,
      2719, 2729, 2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791, 2797, 2801,
      2803, 2819, 2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887, 2897, 2903,
      2909, 2917, 2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999};
  cin >> n;
  int sum = 0, d = 0;
  for (int i = 6; i <= n; i++) {
    d = 0;
    for (int j = 2; j <= i / 2; j++) {
      for (int k = 0; k < 430; k++)
        if (j == a[k]) {
          if (i % j == 0) d++;
          break;
        }
    }
    if (d == 2) sum++;
  }
  cout << sum;
  return 0;
}
