#include<bits/stdc++.h>
int n,m,a[100001],b[100001],x,y;
int t=1;
int ans[100001]={};
using namespace std;
int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++){
		scanf("%d",&a[i]);
	}
	b[1]=a[1];
	for(int i=2;i<=n;i++){
		b[i]=a[i]+b[i-1];
	}
	while(m--){
		scanf("%d%d",&x,&y);
		ans[t++]=b[y]-b[x-1];
	}
	for(int i=1;i<=t-1;i++){
		printf("%d",ans[i]);
		cout<<endl;
	}
	return 0;
}

/**************************************************************
	Problem: 2060
	User: linyifan
	Language: C++
	Result: Time Limit Exceed
****************************************************************/