import java.util.Scanner;
public class Main {
static int[] s;
public static void main(String[] args) {
Scanner in=new Scanner(System.in);
int n=in.nextInt();
int m=in.nextInt();
int[] a=new int[n+1];
s=new int[n+1];
//注意从1开始
for(int i=1;i<=n;i){
a[i]=in.nextInt();
}
s[0]=0;
for(int i=1;i<=n;i){
s[i]=s[i-1]+a[i];
}
while(m–!=0){
int l=in.nextInt();
int r=in.nextInt();
System.out.println(insert(l,r));
}
}
// 求每个区间长度之和
static int insert(int l,int r){
int sum=s[r]-s[l-1];
return sum;
}
}