#include<bits/stdc++.h>
using namespace std;
int n,m,a[100001],b[100001],x,y;
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=b[i-1]+a[i];
	} 
	while(m--){
		scanf("%d%d",&x,&y);
		printf("%d\n",b[y]-b[x-1]);
	}
//cin cout 简易输入输出   当有循环输入或者输出的时候，一定要换成scanf和printf 
//能一半cin cout  一半printf 
}

/**************************************************************
	Problem: 2060
	User: admin
	Language: C++
	Result: Accepted
	Time:261 ms
	Memory:2860 kb
****************************************************************/