#include <bits/stdc++.h>

 using namespace std;

 namespace acm {

 /// count primes between [1..n] (0< n <=1e9)

 /// solution: dp

 /// d(n, i) means that the number of value whose min prime number is bigger than i in [1..n]

 /// d(n, i) = d(n, i-1) if number i is not a prime

 /// d(n, i) = d(n, i-1) - d(n/i, i) + d(i, i-1) if number i is a prime

 /// complex time: O(n^(3/4)), space: O(n^(1/2))

 struct CountPrime {

     int solve(int n) {

         if (n < ) {

             return ;

         }

         dp[] = ;

         int sqrtn = , length = ;

         for (; sqrtn <= n / sqrtn; ++sqrtn) {

             dp[++length] = sqrtn - ;

         }

         for (int i = sqrtn - ; i > ; --i) {

             int val = n / i;

             if (val != i) {

                 dp[++length] = val - ;

             }

         }

         for (int i = ; i < sqrtn; ++i) {

             if (dp[i] == dp[i-]) {

                 continue;

             }

             for (int j=length; j>; --j) {

                 int val = j < sqrtn ? j : n / (length - j + );

                 if (i > val / i) {

                     break;

                 }

                 int pre_statue_pos = val / i;

                 if (pre_statue_pos >= sqrtn) {

                     pre_statue_pos = length - n / pre_statue_pos + ;

                 }

                 dp[j] += dp[i-] - dp[pre_statue_pos];

             }

         }

         return dp[length];

     }

     static const int maxn = 1e5+;

     int dp[maxn];

 };

 } // namespace acm

 int main()

 {

     //freopen("dp.in", "r", stdin);

     //freopen("dp.out", "w", stdout);

     acm::CountPrime cp;

     int n;

     while (scanf ("%d", &n) != EOF) {

         printf ("%d\n", cp.solve(n));

     }

     return ;

 }