View Code of Problem 27

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		for(;;){
		int a = in.nextInt(), b =in.nextInt() ;int sum=0;
		for (int k = a+1; k < b; k++) {
			int d = 1;
			for (int i = 2; i <= k/2; i++) {
				if (k % i == 0)
					d = 0;
			}
			if (d == 1)
				sum+=k;
		}
		System.out.println(sum);
		}
	}
}