#include <bits/stdc++.h>
#define DEBUG
using namespace std;

vector<long long> t;
int n;

void init (int nn)
{
    n = nn;
    t.assign (n, 0);
}

long long sum (int r)
{
    long long result = 0;
    for (; r >= 0; r = (r & (r+1)) - 1)
        result += t[r];
    return result;
}

void inc (int i, long long delta)
{
    for (; i < n; i = (i | (i+1)))
        t[i] += delta;
}

long long sum (int l, int r)
{
    return sum (r) - sum (l-1);
}

void init (vector<int> a)
{
    init ((int) a.size());
    for (unsigned i = 0; i < a.size(); i++)
        inc (i, a[i]);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    freopen("rsq.in", "r", stdin);
    freopen("rsq.out", "w", stdout);
    long long n, m;
    cin >> n >> m;
    vector<int> a(int(1e6), 0);
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    init(a);
    int l, r;
    for(int i = 0; i < m; i++) {
        cin >> l >> r;
        cout << sum(l, r) << "\n";
    }
    return 0;
}