#include<bits/stdc++.h>
using namespace std;
int n,m,e,f;
int a[100002],arr[100002];
int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++){
		scanf("%d",&a[i]);
		arr[i]=a[i]+arr[i-1];
	}
	for(int i=1;i<=m;i++){
		scanf("%d%d",&e,&f);
		printf("%d\n",arr[f]-arr[e-1]);
	}
	return 0;
}

/**************************************************************
	Problem: 2060
	User: chenyongtian
	Language: C++
	Result: Accepted
	Time:236 ms
	Memory:2860 kb
****************************************************************/