#include <iostream>
using namespace std;
int a[1000005];
int main()
{
	int n, m, x, l, r;
	cin >> n >> m;
	for (int i = 1;i <=  n;i++)
	{
		cin >> x;
		a[i] = a[i - 1] + x;// 覆盖原数组
	}
	for (int i = 1;i <= m;i++)
	{
		cin >> l >> r;
		cout << a[r] - a[l - 1] << endl;
                //直接代
	}
	return 0;
}