import java.util.*;

public class Main {

    static final int N = 100010;
    static int[] a = new int[N];
    static int n, m;

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        n = sc.nextInt(); m = sc.nextInt();
        sc.nextLine();

        String[] s = sc.nextLine().split(" ");
        for (int i = 1; i <= n; i++) {
            a[i] = Integer.parseInt(s[i - 1]);
            a[i] += a[i - 1];
        }

        while (m -- > 0) {
            int l = sc.nextInt(), r = sc.nextInt();
            System.out.println(a[r] - a[l - 1]);
        }
    }
}