/*
#include<kyopro/master>
namespace my{entry
void main(){
  LL(N);
  LinearSieve<int>ls(N);
  pp(ls.mobius_enumerate().sum());  
}}*/

#include<bits/stdc++.h>
#if __has_include(<atcoder/all>)
#endif
using namespace std;
#define eb emplace_back
#define RD(T,...) T __VA_ARGS__;lin(__VA_ARGS__)
#define LL(...) RD(ll,__VA_ARGS__)
#define fo(i,...) for(auto[i,i##stop,i##step]=for_range<ll>(0,__VA_ARGS__);i<i##stop;i+=i##step)
#define fe(a,e,...) for(auto&&__VA_OPT__([)e __VA_OPT__(,__VA_ARGS__]):a)
#define defpp template<ostream&o=cout>void pp(const auto&...a){[[maybe_unused]]const char*c="";((o<<c<<a,c=" "),...);o<<'\n';}void epp(const auto&...a){pp<cerr>(a...);}
#define entry defpp void main();void main2();}int main(){my::io();my::main();}namespace my{
namespace my{
void io(){cin.tie(nullptr)->sync_with_stdio(0);cout<<fixed<<setprecision(15);}
using ll=long long;
using i8=int8_t;
template<class T>constexpr auto for_range(T s,T a,T b,T c=1){return array{a-s,b,(1-s*2)*c};}
void lin(auto&...a){(cin>>...>>a);}
template<class A,class B=A>struct pair{
  A a;B b;
  pair()=default;
  pair(A a,B b):a(a),b(b){}
  auto operator<=>(const pair&)const=default;
};
template<class...A>using pack_back_t=tuple_element_t<sizeof...(A)-1,tuple<A...>>;
}
namespace my{
template<class V>concept vectorial=is_base_of_v<vector<typename remove_cvref_t<V>::value_type>,remove_cvref_t<V>>;
template<class T>struct core_t_helper{using type=T;};
template<class T>using core_t=core_t_helper<T>::type;
template<class V>struct vec;
template<int D,class T>struct hvec_helper{using type=vec<typename hvec_helper<D-1,T>::type>;};
template<class T>struct hvec_helper<0,T>{using type=T;};
template<int D,class T>using hvec=hvec_helper<D,T>::type;
template<class V>struct vec:vector<V>{
  using C=core_t<V>;
  using vector<V>::vector;
  auto&emplace_back(auto&&...a){vector<V>::emplace_back(std::forward<decltype(a)>(a)...);return*this;}
  template<class T=C>auto fold(auto&&f)const{
    pair<T,bool>res{};
    fe(*this,e){
      if constexpr(!vectorial<V>){
        if(res.b)f(res.a,e);
        else res={e,1};
      }else { }

    }
    return res;
  }
  template<class T=C>auto sum()const{return fold<T>([](auto&a,const auto&b){a+=b;}).a;}
};
template<class...A>requires(sizeof...(A)>=2)vec(const A&...a)->vec<hvec<sizeof...(A)-2,pack_back_t<A...>>>;
}
namespace my{
ll mobius_prime_pow(ll,i8 k,ll){return-(k==1);}
}
namespace my{
template<class T>class LinearSieve{
public:
  T n;
  vec<int>lpf;
  vec<i8>lpf_ord;
  vec<int>lpf_pow;
  vec<int>lpf_pow_except;
  vec<int>primes;
  LinearSieve(T n):n(n),lpf(n+1,-1),lpf_ord(n+1),lpf_pow(n+1),lpf_pow_except(n+1){
    lpf[1]=lpf_ord[1]=lpf_pow[1]=lpf_pow_except[1]=1;

    fo(i,2,n+1){
      if(lpf[i]==-1)primes.eb(lpf[i]=i);

      fe(primes,p){
        if(p*i>n||p>lpf[i])break;
        lpf[p*i]=p;
      }

      int j=i/lpf[i];
      lpf_ord[i]=lpf_ord[j]*(lpf[i]==lpf[j])+1;
      lpf_pow[i]=((lpf_pow[j]-1)*(lpf[i]==lpf[j])+1)*lpf[i];
      lpf_pow_except[i]=i/lpf_pow[i];
    }
  }
  auto multiplicative_function_enumerate(const auto&f)const{
    vec<T>r(n+1);
    r[1]=1;
    fo(i,2,n+1)r[i]=f(lpf[i],lpf_ord[i],lpf_pow[i])*r[lpf_pow_except[i]];
    return r;
  }
  auto mobius_enumerate()const{return multiplicative_function_enumerate(mobius_prime_pow);}
};
}
namespace my{entry
void main(){
  LL(N);
  LinearSieve<int>ls(N);
  pp(ls.mobius_enumerate().sum());
}}