구름레벨 - Binary Search

import java.io.*;
import java.util.*;
 
class Main {
    private static Scanner sc = new Scanner(System.in);
 
    public static void main(String[] args) throws Exception {
        int len = sc.nextInt();
        int[] num = new int[len];
 
        for(int i = 0; i < num.length; i++){
            num[i] = sc.nextInt();
        }
 
        int[] sum = new int[2];
 
        for(int i = 0; i < sum.length; i++){
            sum[i] = sc.nextInt();
        }
 
        int temp = 0;
 
        for(int i = sum[0] - 1; i < sum[1]; i++){
            temp += num[i];
        }
 
        System.out.print(temp);
    }
}