#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
namespace my{
#define eb emplace_back
#define LL(...) ll __VA_ARGS__;lin(__VA_ARGS__)
#define FO(n) for(ll ij=n;ij-->0;)
#define FOR(i,...) for(auto[i,i##stop,i##step]=range(0,__VA_ARGS__);i<i##stop;i+=i##step)
#define fo(i,...) FO##__VA_OPT__(R)(i __VA_OPT__(,__VA_ARGS__))
#define of(i,...) for(auto[i,i##stop,i##step]=range(1,__VA_ARGS__);i>=i##stop;i+=i##step)
#define fe(a,i,...) for(auto&&__VA_OPT__([)i __VA_OPT__(,__VA_ARGS__]):a)
#define single_testcase void solve();}int main(){my::io();my::solve();}namespace my{
void io(){cin.tie(nullptr)->sync_with_stdio(0);cout<<fixed<<setprecision(15);}
using ll=long long;
constexpr auto range(bool s,auto...a){array<ll,3>r{0,0,1};ll I=0;((r[I++]=a),...);if(!s&&I==1)swap(r[0],r[1]);r[0]-=s;if(s)r[2]*=-1;return r;}
constexpr char newline=10;
constexpr char space=32;
auto ceil(auto x,auto y){if(y<0)x=-x,y=-y;return x<=0?x/y:(x-1)/y+1;}
auto max(auto...a){return max(initializer_list<common_type_t<decltype(a)...>>{a...});}

template<class A,class B>struct pair{
  A a;B b;
  pair()=default;
  pair(A a,B b):a(a),b(b){}
  pair(const std::pair<A,B>&p):a(p.first),b(p.second){}
  auto operator<=>(const pair&)const=default;
  pair operator+(const pair&p)const{return{a+p.a,b+p.b};}
  friend istream&operator>>(istream&i,pair&p){return i>>p.a>>p.b;}
  friend ostream&operator<<(ostream&o,const pair&p){return o<<p.a<<space<<p.b;}
};

template<class T,class U>ostream&operator<<(ostream&o,const std::pair<T,U>&p){return o<<p.first<<space<<p.second;}

template<ll k>auto pack_kth(const auto&...a){return get<k>(make_tuple(a...));}
template<class T,size_t...I>auto pack_slice_impl(index_sequence<I...>, const auto&...a){return array<T,sizeof...(I)>{get<I>(forward_as_tuple(a...))...};}
template<class T,size_t n>auto pack_slice(const auto&...a){return pack_slice_impl<T>(make_index_sequence<n>{},a...);}

template<class V>concept vectorial=is_base_of_v<vector<typename V::value_type>,V>;
template<class T>struct vec_attr{using core_type=T;static constexpr int rank=0;};
template<vectorial V>struct vec_attr<V>{using core_type=typename vec_attr<typename V::value_type>::core_type;static constexpr int rank=vec_attr<typename V::value_type>::rank+1;};
template<class T>using core_t=vec_attr<T>::core_type;
template<class V>istream&operator>>(istream&i,vector<V>&v){fe(v,e)i>>e;return i;}
template<class V>ostream&operator<<(ostream&o,const vector<V>&v){fe(v,e)o<<e<<string(&e!=&v.back(),vectorial<V>?newline:space);return o;}

template<class V>struct vec:vector<V>{
  using vector<V>::vector;
  vec(const vector<V>&v){vector<V>::operator=(v);}

  template<class...A>requires(sizeof...(A)>=3)vec(A...a){const ll n=sizeof...(a)-1;auto t=pack_slice<ll,n>(a...);ll s[n];fo(i,n)s[i]=t[i];*this=make_vec(s,pack_kth<n>(a...));}
  template<class T,ll n,ll i=0>static auto make_vec(const ll(&s)[n],T x){if constexpr(i==n-1)return vec<T>(s[i],x);else{auto X=make_vec<T,n,i+1>(s,x);return vec<decltype(X)>(s[i],X);}}

  vec&operator^=(const vec&u){this->insert(this->end(),u.begin(),u.end());return*this;}
  vec operator^(const vec&u)const{return vec{*this}^=u;}
  vec&operator+=(const vec&u){vec&v=*this;fo(i,v.size())v[i]+=u[i];return v;}
  vec&operator-=(const vec&u){vec&v=*this;fo(i,v.size())v[i]-=u[i];return v;}
  vec operator+(const vec&u)const{return vec{*this}+=u;}
  vec operator-(const vec&u)const{return vec{*this}-=u;}
  vec&operator++(){fe(*this,e)++e;return*this;}
  vec&operator--(){fe(*this,e)--e;return*this;}
  vec operator-()const{vec v=*this;fe(v,e)e=-e;return v;}

  ll size()const{return vector<V>::size();}

  auto pop_back(){auto r=this->back();vector<V>::pop_back();return r;}

  auto scan(const auto&f)const{pair<core_t<V>,bool>r{};fe(*this,e)if constexpr(!vectorial<V>)r.b?f(r.a,e),r:r={e,1};else if(auto s=e.scan(f);s.b)r.b?f(r.a,s.a),r:r=s;return r;}
  auto max()const{return scan([](auto&a,const auto&b){a<b?a=b:0;}).a;}
};
template<ll rank,class T>struct tensor_helper{using type=vec<typename tensor_helper<rank-1,T>::type>;};
template<class T>struct tensor_helper<0,T>{using type=T;};
template<ll rank,class T>using tensor=typename tensor_helper<rank,T>::type;
template<class...A>requires(sizeof...(A)>=2)vec(A...a)->vec<tensor<sizeof...(a)-2,remove_reference_t<decltype(get<sizeof...(a)-1>(declval<tuple<A...>>()))>>>;
vec(ll)->vec<ll>;

void lin(auto&...a){(cin>>...>>a);}
template<char c=space>void pp(const auto&...a){ll n=sizeof...(a);((cout<<a<<string(--n>0,c)),...);cout<<newline;}

constexpr uint64_t kth_root_floor(uint64_t a,ll k){
  if (k==1)return a;
  auto within=[&](uint32_t x){uint64_t t=1;fo(k)if(__builtin_mul_overflow(t,x,&t))return false;return t<=a;};

  uint64_t r=0;
  of(i,sizeof(uint32_t)*CHAR_BIT)if(within(r|(1u<<i)))r|=1u<<i;
  return r;
}
template<class T>constexpr T sqrt_floor(T x){return kth_root_floor(x,2);}

enum{COUNTER_CLOCKWISE,CLOCKWISE,ONLINE_BACK,ONLINE_FRONT,ON_SEGMENT};
enum{IN,ON,OUT};

template<class T>auto prime_enumerate(T n){
  vec<bool>sieve(n/3+1,1);
  for(T p=5,d=4,i=1,rn=sqrt_floor(n);p<=rn;p+=d=6-d,i++){
    if(!sieve[i])continue;
    for(T q=(p*p)/3,r=d*p/3+(d*p%3==2),s=p*2;q<sieve.size();q+=r=s-r)sieve[q]=0;
  }
  vec<T>r{2,3};
  for(T p=5,d=4,i=1;p<=n;p+=d=6-d,i++)if(sieve[i])r.eb(p);
  while(r.size()&&r.back()>n)r.pop_back();
  return r;
}

template<class T>auto interval_square_and_square_free_enumerate(T L,T R=-1){
  if(R==-1)R=L+1,L=0;
  vec<pair<T,T>>r(R-L);
  fo(i,L,R)r[i-L]={1,T(i)};
  fe(prime_enumerate(sqrt_floor(R-1)),p){
    auto p2=p*p;
    fo(i,max(ceil(L,p2),1)*p2,R,p2){
      while(r[i-L].b%p2==0){
        r[i-L].b/=p2;
        r[i-L].a*=p;
      }
    }
  }
  return r;
}

single_testcase
void solve(){
  LL(N);

  auto v=interval_square_and_square_free_enumerate<int>(N);
  ll ans=0;
  fo(a,1,N+1){
    auto[m,k]=v[a];
    ans+=sqrt_floor(N/k);
  }
  pp(ans);
}}