#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<long long>;

#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define rep(i, a, b) for (int i = (a); i < (b); i++)

mt19937 rng(random_device{}());

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	long long N;
	cin >> N;

	if(N >= 614889782588491410){
		cout << "15\n";
		return 0;
	}
	
	if(N < 6){
		cout << "1\n";
		return 0;
	}
 
	vector <ll> limit;
	vector <int> primes = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47};
	ll cur = 2;

	rep(i, 1, 15){
		cur *= primes[i];
		limit.pb(cur);
	}

	/*for(auto a : limit){
		cerr << a << " ";
	}

	cerr << endl;*/

	rep(i, 0, 15){
		if(N == limit[i]){
			cout << i+2 << "\n";
			return 0;
		}
		else if(N < limit[i]){
			cout << i+1 << "\n";
			return 0;
		}
	}

	return 0;
}