#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
int n,sum,j,s[1000001],a[1000001];
int main()
{
    cin>>n>>j;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		s[i]=s[i-1]+a[i];
	}    
    while(j--){
    	int l,r;
    	scanf("%d%d",&l,&r);
    	cout<<s[r]-s[l-1]<<endl;
	}
    return 0;
}