#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); i ++)
using namespace std;
using ll = long long;
using PL = pair<ll,ll>;
using P = pair<int,int>;
constexpr int INF = 1000000000;
constexpr long long HINF = 1000000000000000;
constexpr long long MOD = 1000000007;// = 998244353;
constexpr double EPS = 1e-4;
constexpr double PI = 3.14159265358979;

int main() {
    int N,K,M; cin >> N >> K >> M;
    vector<ll> A(N + 1);
    rep(i,N) cin >> A[i];
    A.back() = 0;
    for (int i = N - 1;i >= 0;--i) A[i] += A[i + 1]; 

    vector<ll> dp(N + 1,0);
    rep(i,N) dp[i + 1] = abs(A[0] - A[i + 1]);
    
    for (int i = 1;i < K;++i) {
        vector<ll> plus(N + 1),minus(N + 1);
        plus[0] = dp[0]; minus[0] = dp[0];
        rep(j,N) {
            plus[j + 1] = dp[j + 1] + A[j + 1];
            minus[j + 1] = dp[j + 1] - A[j + 1];
        }
        
        deque<int> dq;
        dq.push_back(0);
        rep(j,N) {
            while (!dq.empty() && dq.front() <= j - M) dq.pop_front();
            if (!dq.empty()) dp[j + 1] = max(dp[j + 1],plus[dq.front()] - A[j + 1]);
            while (!dq.empty() && plus[dq.front()] <= plus[j + 1]) dq.pop_front();
            dq.push_back(j + 1);
        }
        dq.clear();
        dq.push_back(0);
        rep(j,N) {
            while (!dq.empty() && dq.front() <= j - M) dq.pop_front();
            if (!dq.empty()) dp[j + 1] = max(dp[j + 1],minus[dq.front()] + A[j + 1]);
            while (!dq.empty() && minus[dq.front()] <= minus[j + 1]) dq.pop_front();
            dq.push_back(j + 1);
        }
    }
    cout << dp.back() << '\n';
    return 0;
}