#include <iostream>
#include <bits/stdc++.h>
using namespace std;

int main() {
	int n,q	;
	cin>>n>>q;
	vector<long long>arr(n);
	for (int i = 0; i < n; i++) {
		cin>>arr[i];
	}
	 vector<long long> prefix(n + 1, 0);
    for (int i = 0; i < n; i++) {
        prefix[i + 1] = prefix[i] + arr[i];
    }
    for(int i=0;i<q;i++){
    	int r,l;
    	cin>>r>>l;
    	cout<<prefix[r+1]-prefix[l]<<endl;
    }
    
	return 0;
}