#include<bits/stdc++.h>
using namespace std;
int n,m,a[1000000],b[1000000],k,l;
int main(){
	cin>>k>>l;
	for(int i=1;i<=k;i++){
		cin>>a[i];
		a[i]=a[i]+a[i-1];
	}
	for(int i=1;i<=l;i++){
		cin>>n>>m;
		b[i]=a[m]-a[n-1];
	}
	for(int i=1;i<=l;i++){
		cout<<b[i]<<endl;
	}
} 
/**************************************************************
	Problem: 2060
	User: zhengzihao
	Language: C++
	Result: Time Limit Exceed
****************************************************************/