import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int m = sc.nextInt();
int[] arr = new int[n];
int[] Sn = new int[100010];
for(int i = 0;i<n;i++){
arr[i]=sc.nextInt();
Sn[i+1]= arr[i] + Sn[i];
}
while(m-- != 0){
int l = sc.nextInt();
int r = sc.nextInt();
System.out.println(Sn[r]-Sn[l-1]);
}
}
}