#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--){
		cin>>x>>y;
		cout<<b[y]-b[x-1]<<endl;
	}

}

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