#include <iostream>
#include <algorithm>

using namespace std;

const int N = 1e5 + 10;
int n, m;
int a[N];
int s[N];

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

    for (int i = 1; i <= n; i ++) s[i] = s[i - 1] + a[i];

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

    return 0;
}