View Code of Problem 27

import java.util.Scanner;

public class Main {
    public static boolean su(int num) {
        if(num == 1) {
            return false;
        }
        else {
            for(int i = 2;i <= Math.sqrt(num);i++) {
                if(num % i == 0) {
                    return false;
                }
            }
            return true;
        }
    }
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNext()) {
            int a = scanner.nextInt();
            int b = scanner.nextInt();
            int sum = 0;
            for(int i = a + 1;i < b;i++) {
                if(su(i)) {
                    sum += i;
                }
            }
            System.out.println(sum);
        }
    }
}