#include <bits/stdc++.h>
#define endl '\n'
using namespace std;

int n, m;
int arr[100100];
int dp[100100];
int x, y; 

int main(){
	cin >> n >> m;
	for(int i = 1; i <= n; i++){
		cin >> arr[i];
		dp[i] = dp[i - 1] + arr[i];
	}
	for(int i = 1; i <= m; i++){
		cin >> x >> y;
		cout << dp[y] - dp[x - 1] << endl;
	}
	
	
	
	return 0;
}