#include<bits/stdc++.h>
using namespace std;
int n,m,a[100001],b[100001],x,y;
int main(){
	cin>>n>>m; 
	for(int i;i<=n;i++){
		cin>>a[i];
		b[i]=a[i]+b[i-1];
	} 
	while(m--){
		scanf("%d%d",x,y);
		printf("%d\n",b[y]-b[x-1]);
	}

	return 0;
}

/**************************************************************
	Problem: 2060
	User: zhengyuxuan
	Language: C++
	Result: Runtime Error
****************************************************************/