백준 9단계(1929)

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;
 
public class Main {
 
    //3 16
    //result
    //3
    //5
    //7
    //11
    //13
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        
        String str = br.readLine();
        StringTokenizer st = new StringTokenizer(str);
        int start = Integer.parseInt(st.nextToken());
        int end = Integer.parseInt(st.nextToken());
        
        boolean[] bool = new boolean[end + 1];
        for(int i = 2; i < bool.length; i++) {
            bool[i] = true;
        }
        
        for(int i = 2; i < Math.sqrt(bool.length); i++) {
            if(bool[i]) {
                for(int j = i * i; j < bool.length; j += i) {
                    bool[j] = false;
                }
            }
        }
        
        for(int i = start; i <= end; i++) {
            if(bool[i]) bw.write(String.valueOf(i) + "\n");
        }
        bw.flush();
        
    }
}