#include<iostream>

using namespace std;
const int N = 100010;
int a[N];
int n, m;

int main()
{
    cin >> n >> m;
    for(int i = 1; i <= n; i ++) cin >> a[i], a[i] += a[i - 1];

    while(m --)
    {
        int l, r;
        cin >> l >> r;
        cout << a[r] - a[l - 1] << endl;

    }

    return 0;
}