#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using VL = vector<ll>;
#define FOR(i,a,n) for(int i=(a);i<(n);++i)
#define eFOR(i,a,n) for(int i=(a);i<=(n);++i)
#define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i)
#define all(i) i.begin(),i.end()
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
template<class T>inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; }
inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); }

int main() {
    init();

    int n, k, m; cin >> n >> k >> m;
    assert(1 <= n && n <= 5000);
    assert(1 <= k && k <= n);
    assert(1 <= m && m <= n);
    assert(n <= m * k);
    VL a(n + 1);
    FOR(i, 0, n)cin >> a[i];
    assert(-INF <= *min_element(all(a)) && *max_element(all(a)) <= INF);

    rFOR(i, 0, n)a[i] += a[i + 1];
    vector<deque<pair<int, ll>>> plus(k), minus(k);
    plus[0].emplace_back(-1, a[0]), minus[0].emplace_back(-1, -a[0]);
    vector<VL> dp(2, VL(k + 1, -LLINF));
    FOR(i, 0, n) {
        eFOR(j, 0, k)dp[(i + 1) & 1][j] = 0;
        rFOR(j, 0, k) {
            while (!plus[j].empty() && plus[j].front().first < i - m)plus[j].pop_front();
            while (!minus[j].empty() && minus[j].front().first < i - m)minus[j].pop_front();
            if (!plus[j].empty())chmax(dp[(i + 1) & 1][j + 1], plus[j].front().second - a[i + 1]);
            if (!minus[j].empty())chmax(dp[(i + 1) & 1][j + 1], minus[j].front().second + a[i + 1]);
            if (j + 1 < k) {
                while (!plus[j + 1].empty() && plus[j + 1].back().second <= dp[(i + 1) & 1][j + 1] + a[i + 1])plus[j + 1].pop_back();
                while (!minus[j + 1].empty() && minus[j + 1].back().second <= dp[(i + 1) & 1][j + 1] - a[i + 1])minus[j + 1].pop_back();
                plus[j + 1].emplace_back(i, dp[(i + 1) & 1][j + 1] + a[i + 1]);
                minus[j + 1].emplace_back(i, dp[(i + 1) & 1][j + 1] - a[i + 1]);
            }
        }
    }

    cout << dp[n & 1][k] << "\n";

    return 0;
}