//  Static Range Sum Queries

#include<bits/stdc++.h>

using namespace std;
using ll = long long;

int main() {
    int n, q; cin >> n >> q;
    vector<ll> pref(n, 0);
    ll x; cin >> x;
    pref[0] = x;
    for (int i = 1; i < n; i ++) {
        ll y; cin >> y;
        pref[i] = y + pref[i-1];
    }
    for (int i{}; i < q; i++) {
        int a, b; cin >> a >> b;
        if (a >= 2 ) cout << pref[b - 1] - pref[a - 2] << endl;
        else cout << pref[b - 1] << endl;
    }

    return 0;
}