Javaの場合の素数計算

import java.io.*;

public class Prime
{
	static int FIRST_PRIME = 2;
	
	public static boolean is_prime(int i){
		for(int n=FIRST_PRIME; n<i-1; n++){
			if(i%n == 0){
				return false;
			}
		}
		return true;
	}
	
	public static void main(String[] args) throws IOException{
		
		BufferedReader br =
			new BufferedReader(new InputStreamReader(System.in));
			
		String str = br.readLine();
		int n = Integer.parseInt(str);
		
		for(int i=0; i<n; i++){
			if(is_prime(i) && i >= FIRST_PRIME){
				System.out.println(i);				
			}
		}
		
		System.exit(0);	
	}
}