#include<bits/stdc++.h>
using namespace std;
int n,m,x,y;
int a[100001];
int b[100001];
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=a[i]+b[i-1];
	}
	for(int i=1;i<=m;i++){
		cin>>x>>y;
		cout<<b[y]-b[x-1]<<endl;
		
	}
	


	return 0;
}

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