#include<bits/stdc++.h>
using namespace std;
int n,m,x,y,a[100000],b[100000]; 
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=a[i]+b[i-1];
	}
	while(m--){
		scanf("%d%d",&y&y);
		printy("%d\n",b[y]-b[x-1]);
	}
}
/**************************************************************
	Problem: 2060
	User: zhangzekai
	Language: C++
	Result: Compile Error
****************************************************************/