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

typedef long long int LL;

const LL MAX_N = 3000005;

int n, k, q;
LL a[MAX_N], prefSums[MAX_N];
unordered_map<LL, LL> cache;
vector<LL> queries;
unordered_map<int, int> maxRights;

bool DEBUG = false;

LL hashPair(const LL left, const LL right)
{
    return left*MAX_N + right;
}

LL solve(int left, int right)
{
    auto existingIt = cache.find(hashPair(left, right));
    if(existingIt != cache.cend())
    {
        return existingIt->second;
    }

    vector<LL> dp(n+1);
    LL maxOverall = 0;

    LL maxPrev = 0;
    for(int i = left+k-1; i <= right; ++i)
    {
        if(i-k >= left)
        {
            maxPrev = max(maxPrev, dp[i-k]);
        }

        dp[i] = prefSums[i]-prefSums[i-k];

        if(maxPrev > 0)
        {
            dp[i] += maxPrev;
        }

        if(dp[i] > maxOverall)
        {
            maxOverall = dp[i];
        }

        cache[hashPair(left, i)] = maxOverall;

        //cout << "i: " << i << ", dp[i]: " << dp[i] << endl;
    }

    return maxOverall;
}

int main()
{
    ios_base::sync_with_stdio(0);

    cin >> n >> k >> q;
    for(int i = 1; i <= n; ++i)
    {
        cin >> a[i];
        prefSums[i] = prefSums[i-1] + a[i];
    }

    int l, r;
    for(int i = 0; i < q; ++i)
    {
        cin >> l >> r;

        queries.push_back(hashPair(l, r));
        maxRights[l] = max(maxRights[l], r);
    }

    for(const auto& query : maxRights)
    {
        solve(query.first, query.second);
    }

    for(const auto& query : queries)
    {
        cout << cache[query] << endl;
    }

    return 0;
}