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+1];
int [] S =new int[n+1];
S[0]=0;
for(int i = 1;i<=n;i++){
arr[i]=sc.nextInt();
}
for(int j=1;j<=n;j++){
S[j]=S[j-1]+arr[j];
}
while(m-->0){
int l=sc.nextInt();
int r=sc.nextInt();
System.out.println(S[r]-S[l-1]);
}
}
}