#include "bits/stdc++.h"
using namespace std;

#define int int64_t
#define trav(i, a) for(auto& i: a)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define si(a) ((int)(a).size())
#define ins insert
#define pb push_back
#define mp make_pair
#define f first
#define s second

const int MOD = 1e9 + 7;
const int INF = 1e18;
const string nl = "\n";

struct timer {
	decltype(chrono::high_resolution_clock::now()) begin;
	void start() {
		begin = chrono::high_resolution_clock::now();
	}
	void end() {
		auto end = chrono::high_resolution_clock::now();
		auto duration = chrono::duration_cast<chrono::milliseconds>(end - begin).count();
		cerr << duration << "ms elapsed" << endl;
	}
};

const int N = 1e8;

vector<bool> isp(N, true);

void sieve() {
	isp[0] = isp[1] = 0;
	for(int i = 2; i < N; ++i) {
		if(!isp[i]) {
			continue;
		}
		for(int j = i * i; j < N; j += i) {
			isp[j] = false;
		}
	}
}

vector<bool> is_prime(N, true);

void sieve1() {
	is_prime[0] = is_prime[1] = 0;
	for(int i = 2; i < N; ++i) {
		for(int j = i * i; j < N; j += i) {
			is_prime[j] = false;
		}
	}
}

int32_t main() {
	ios::sync_with_stdio(0);
	cin.tie(nullptr);

	timer a;
	a.start();
	sieve();
	a.end();
	a.start();
	sieve1();
	a.end();
}