#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,a,b[100000];
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		cin>>a;
		b[i]=b[i-1]+a;
	}
	for(int i=1;i<=m;i++)
	{
		int x,y;
		cin>>x>>y;
		cout<<b[y]-b[x-1]<<endl;
	}
}
/**************************************************************
	Problem: 2060
	User: wuyunfeng
	Language: C++
	Result: Time Limit Exceed
****************************************************************/