#include<bits/stdc++.h>
using namespace std;
int n,m,a[100000],b[100000],l,r;

int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=a[i]+b[i-1]; 
	//	cout<<b[i]<<" "; 
		
	} 
	while(m--){
		cin>>l>>r;
		cout<<b[r]-b[l-1]<<endl;
	}


}

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