#include<bits/stdc++.h>
using namespace std;
int m,n; 
int 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];
	}
	for(int i=1;i<=m;i++){
		scanf("%d%d",&x,&y);
		printf("%d",b[y]-b[x-1]);
		cout<<endl;
	}
	return 0;
}
/**************************************************************
	Problem: 2060
	User: lujiaye
	Language: C++
	Result: Time Limit Exceed
****************************************************************/