#line 2 "cpplib/util/template.hpp"
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")
#include<bits/stdc++.h>
using namespace std;
struct __INIT__{__INIT__(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}}__INIT__;
typedef long long lint;
#define INF (1LL<<60)
#define IINF (1<<30)
#define EPS (1e-10)
#define endl ('\n')
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
template<typename T>using V=vector<T>;
template<typename T>using VV=V<V<T>>;
template<typename T>inline void output(T t){bool f=0;for(auto i:t){cout<<(f?" ":"")<<i;f=1;}cout<<endl;}
template<typename T>inline void output2(T t){for(auto i:t)output(i);}
template<typename T>inline void debug(T t){bool f=0;for(auto i:t){cerr<<(f?" ":"")<<i;f=1;}cerr<<endl;}
template<typename T>inline void debug2(T t){for(auto i:t)output(i);}
#define loop(n) for(long long _=0;_<(long long)(n);++_)
#define rep(i,...) for(auto i:range(__VA_ARGS__)) 
#define rrep(i,...) for(auto i:reversed(range(__VA_ARGS__)))
#define repi(i,a,b) for(lint i=lint(a);i<(lint)(b);++i)
#define rrepi(i,a,b) for(lint i=lint(b)-1;i>=lint(a);--i)
#define irep(i) for(lint i=0;;++i)
inline vector<long long> range(long long n){if(n<=0)return vector<long long>();vector<long long>v(n);iota(v.begin(),v.end(),0LL);return v;}
inline vector<long long> range(long long a,long long b){if(b<=a)return vector<long long>();vector<long long>v(b-a);iota(v.begin(),v.end(),a);return v;}
inline vector<long long> range(long long a,long long b,long long c){if((b-a+c-1)/c<=0)return vector<long long>();vector<long long>v((b-a+c-1)/c);for(int i=0;i<(int)v.size();++i)v[i]=i?v[i-1]+c:a;return v;}
template<typename T>inline T reversed(T v){reverse(v.begin(),v.end());return v;}
#define all(n) begin(n),end(n)
template<typename T,typename E>bool chmin(T& s,const E& t){bool res=s>t;s=min<T>(s,t);return res;}
template<typename T,typename E>bool chmax(T& s,const E& t){bool res=s<t;s=max<T>(s,t);return res;}
const vector<lint> dx={1,0,-1,0,1,1,-1,-1};
const vector<lint> dy={0,1,0,-1,1,-1,1,-1};
#define SUM(v) accumulate(all(v),0LL)
template<typename T,typename ...Args>auto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector<T>(arg,x);else return vector(arg,make_vector<T>(x,args...));}
#define extrep(v,...) for(auto v:__MAKE_MAT__({__VA_ARGS__}))
vector<vector<long long>> __MAKE_MAT__(vector<long long> v){if(v.empty())return vector<vector<long long>>(1,vector<long long>());long long n=v.back();v.pop_back();vector<vector<long long>> ret;vector<vector<long long>> tmp=__MAKE_MAT__(v);for(auto e:tmp)for(long long i=0;i<n;++i){ret.push_back(e);ret.back().push_back(i);}return ret;}
using graph=vector<vector<int>>;
template<typename T>using graph_w=vector<vector<pair<int,T>>>;
template<typename T,typename E>ostream& operator<<(ostream& out,pair<T,E>v){out<<"("<<v.first<<","<<v.second<<")";return out;}
#line 6 "cpplib/math/prime_list.hpp"

/**
 * @brief 素数列挙
 */

std::bitset<500'000'001> p;
std::vector<long long> prime_list(int n) {
    p.set();
    p[0]=0;
    for(int i=2;i*i<=n;++i){
        if(!p[i])continue;
        for(int j=2*i;j<=n;j+=i)p[j]=0;
    }
    std::vector<long long>list;
    for(int i=2;i<=n;++i)if(p[i])list.push_back(i);
    return list;
}

#line 2 "cpplib/math/is_prime.hpp"
#include <initializer_list>
/**
 * @brief 素数判定(高速)
 */
bool is_prime(long long n){
    if(n<=1)return 0;
    if(n==2)return 1;
    if(n%2==0)return 0;
    long long s=0,d=n-1;
    while(d%2)d/=2,s++;
    auto mod_pow=[](__int128_t a,__int128_t b,__int128_t n){
        long long res=1;
        while(b){
            if(b%2)res=res*a%n;
            a=a*a%n;
            b/=2;
        }
        return (long long)(res);
    };
    for(long long e:{2,3,5,7,11,13,17,19,23,29,31,37}){
        if(n<=e)break;
        if(mod_pow(e,d,n)==1)continue;
        bool b=1;
        for(int i=0;i<s;i++){
            if(mod_pow(e,d<<i,n)==n-1)b=0;
        }
        if(b)return 0;
    }
    return 1;
}
#line 4 "code.cpp"
int main(){
    lint n;
    cin>>n;
    auto v=prime_list(20000001);
    vector<unordered_map<lint,lint>>m(100000);
    map<lint,lint>memo;
    auto dfs=[&](auto dfs,lint i,lint n)->lint{
        if(n==0)return 0;
        if(m[i].count(n))return m[i][n];
        if(n<=(v[i]-1)*(v[i]-1)){
            lint res=n;
            lint l=v[i]-1,r=0;
            while(l<=n){
                r=n/(n/l)+1;
                if(v[i]<=r&&(r<20000001?p[r]:is_prime(r))){
                    res++;
                }
                l=r;
            }
            m[i][n]=res;
            return res;
        }
        lint res=0;
        if(n/(v[i]-1)==n/v[i])res=dfs(dfs,i+1,n);
        else res=dfs(dfs,i+1,n)+dfs(dfs,i+1,n/(v[i]-1))-dfs(dfs,i+1,n/v[i]);
        m[i][n]=res;
        return res;
    };
    cout<<dfs(dfs,0,n)<<endl;
}