#include <iostream>
#include <cmath>
#include <vector>
using namespace std;

bool isPrimeNumber(const unsigned long n);

int main(){
    unsigned long n;
    vector<unsigned long> pri;
    while(cin>>n){
        unsigned ans = 0;
        for(unsigned long i=1;i<=n;i--){
            bool serch = true;
            vector<unsigned long>::iterator it = pri.begin();
            while(it!=pri.end()){
                if(fmodl(n,*it)==0){
                    ans++;
                    serch = false;
                    break;
                }
            }
            if(isPrimeNumber(i)&&serch){
                ans++;
                pri.push_back(i);
            }
        }
        cout << ans << endl;
    }
}

bool isPrimeNumber(const unsigned long n){
    static const unsigned long carn[]{
        561,	1105,	1729,	2465,	2821,	6601,	8911,
        10585,	15841,	29341,	41041,	46657,	52633,	62745,	63973,	75361,
        101101,	115921,	126217,	162401,	172081,	188461,	252601,	278545,	294409,
        314821,	334153,	340561,	399001,	410041,	449065,	488881,	512461,	530881,
        552721,	656601,	658801,	670033,	748657,	825265,	838201,	852841,	997633,
        1024651,1033669,1050985,1082809,1152271,1193221,1461241,1569457,1615681,
        1773289,1857241,1909001,2100901,2113921,2433601,2455921,2508013,2531845,
        2628073,2704801,3057601,3146221,3224065,3581761,3664585,3828001,4335241,
        4463641,4767841,4903921,4909177,5031181,5049001,5148001,5310721,5444489,
        5481451,5632705,5968873,6049681,6054985,6189121,6313681,6733693,6840001,
        6868261,7207201,7519441,7995169,8134561,8341201,8355841,8719309,8719921,
        8830801,8927101,9439201,9494101,9582145,9585541,9613297,9890881
    };

    if(n==2)
        return true;
    else if(n<2||n%2==0)
        return false;
    else{
        for(unsigned long i=0;i<sizeof(carn)/sizeof(carn[0]);i++){
            if(n<carn[i])
                break;
            if(n==carn[i])
                return false;
        }
        for(unsigned long i=n-1;i>0;i--){
            if(fmodl(powl(i,n),n)!=i)
                return false;
        }
        return true;
    }
}