#include <iostream>
#include <cmath>
#include <fstream>

using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");


int N,i,nrp,p;
bool v[2000000];
int main(){f>>N;
for(i=4;i<=N;i=i+2)v[i]=1;
i=3;
while(i*i<=N){
    for(p=i*i;p<=N;p=p+i*2)v[p]=1;
    i=i+2;}
    for(i=2;i<=N;i++)g<<v[i];
for(i=2;i<=N;i++){if(v[i]==0)nrp++;}
    g<<nrp;
    f.close();
    g.close();

    return 0;

}