#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
constexpr int INF = 1001001001;
// constexpr int mod = 1000000007;
constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, M, K, A;
    cin >> N >> K >> M;
    vector<ll> S(N + 1);
    for(int i = 0; i < N; ++i){
        cin >> A;
        S[i + 1] = S[i] + A;
    }

    constexpr ll inf = 1e+17;
    vector<vector<ll>> dp(2, vector<ll>(N + 1, -inf));
    dp[0][0] = dp[1][0] = 0;
    for(int k = 0; k < K; ++k){
        vector<vector<ll>> dp2(2, vector<ll>(N + 1, -inf));
        vector<deque<ll>> slide_max(2);
        vector<deque<int>> idx(2);
        slide_max[0].push_back(dp[0][0]);
        idx[0].push_back(0);
        slide_max[1].push_back(dp[1][0]);
        idx[1].push_back(0);
        for(int i = 0; i < N; ++i){
            ll maxv = max(slide_max[0].front() + S[i + 1], slide_max[1].front() - S[i + 1]);
            chmax(dp2[0][i + 1], maxv - S[i + 1]);
            chmax(dp2[1][i + 1], maxv + S[i + 1]);
            for(int j = 0; j < 2; ++j){
                if(i + 1 - idx[j].front() >= M){
                    slide_max[j].pop_front();
                    idx[j].pop_front();
                }
                while(slide_max[j].size() && dp[j][i + 1] >= slide_max[j].back()){
                    slide_max[j].pop_back();
                    idx[j].pop_back();
                }
                slide_max[j].push_back(dp[j][i + 1]);
                idx[j].push_back(i + 1);
            }
        }
        dp = move(dp2);
    }

    cout << max(dp[0][N] + S[N], dp[1][N] - S[N]) << '\n';
    
    return 0;
}