#include<bits/stdc++.h>
using namespace std;
int n,m,a[100005],pre[100005],x,y;

int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)scanf("%d",&a[i]);
	for(int i=1;i<=n;i++)pre[i]=pre[i-1]+a[i];
	for(int i=1;i<=m;i++){
		scanf("%d%d",&x,&y);
		printf("%d\n",pre[y]-pre[x-1]);
	}
	return 0;
}
/**************************************************************
	Problem: 2060
	User: godzzw
	Language: C++
	Result: Accepted
	Time:239 ms
	Memory:2860 kb
****************************************************************/