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

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
//typedef vector<vector<ll>> Graph;

//const ll mod = 1e9 + 7;
const ll mod = 998244353;

#define REP(i,n) for(ll i=0;i<(ll)n;i++)
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define spa << " " <<
#define fi first
#define se second

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){
os << "(" << v.first << ", " << v.second << ")"; return os;
}
template<class T> ostream& operator << (ostream& os, const vector<T> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << " ";} os << v[i];} return os;
}
template<class T> ostream& operator << (ostream& os, const vector<vector<T>> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os;
}

template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<endl;}};
template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];
for(ll i=1;i<n;i++)cerr spa v[i];
cerr<<endl;};

template< typename Monoid, typename OperatorMonoid, typename F, typename G, typename H >
struct LazySegmentTree {
  // std::function は遅いので使わないことを推奨
  //using F = function< Monoid(Monoid, Monoid) >;
  //using G = function< Monoid(Monoid, OperatorMonoid) >;
  //using H = function< OperatorMonoid(OperatorMonoid, OperatorMonoid) >;

  int sz, height;
  vector< Monoid > data;
  vector< OperatorMonoid > lazy;
  const F f;
  const G g;
  const H h;
  const Monoid M1;
  const OperatorMonoid OM0;


  // n: サイズ
  // f: 二つの区間をマージする二項演算
  // g: 要素と作用素をマージする二項演算
  // h: 作用素同士をマージする二項演算
  // M1: モノイドの単位元
  // OM0: 作用素の単位元

  // 初期化を忘れない！x を初期値とすると
  // REP(i, n) seg[i].set(x);
  // seg.build();

  // 初期化なしだとM1で初期化される
  // range sum をするときは，M1は(0, 0)だが初期化は(0, 1)であることに注意！

  LazySegmentTree(int n, const F f, const G g, const H h,
                  const Monoid &M1, const OperatorMonoid OM0)
      : f(f), g(g), h(h), M1(M1), OM0(OM0) {
    sz = 1;
    height = 0;
    while(sz < n) sz <<= 1, height++;
    data.assign(2 * sz, M1);
    lazy.assign(2 * sz, OM0);
  }

  void set(int k, const Monoid &x) {
    data[k + sz] = x;
  }

  void build() {
    for(int k = sz - 1; k > 0; k--) {
      data[k] = f(data[2 * k + 0], data[2 * k + 1]);
    }
  }

  inline void propagate(int k) {
    if(lazy[k] != OM0) {
      lazy[2 * k + 0] = h(lazy[2 * k + 0], lazy[k]);
      lazy[2 * k + 1] = h(lazy[2 * k + 1], lazy[k]);
      data[k] = reflect(k);
      lazy[k] = OM0;
    }
  }

  inline Monoid reflect(int k) {
    return lazy[k] == OM0 ? data[k] : g(data[k], lazy[k]);
  }

  inline void recalc(int k) {
    while(k >>= 1) data[k] = f(reflect(2 * k + 0), reflect(2 * k + 1));
  }

  inline void thrust(int k) {
    for(int i = height; i > 0; i--) propagate(k >> i);
  }

  void update(int a, int b, const OperatorMonoid &x) {
    thrust(a += sz);
    thrust(b += sz - 1);
    for(int l = a, r = b + 1; l < r; l >>= 1, r >>= 1) {
      if(l & 1) lazy[l] = h(lazy[l], x), ++l;
      if(r & 1) --r, lazy[r] = h(lazy[r], x);
    }
    recalc(a);
    recalc(b);
  }

  Monoid query(int a, int b) {
    thrust(a += sz);
    thrust(b += sz - 1);
    Monoid L = M1, R = M1;
    for(int l = a, r = b + 1; l < r; l >>= 1, r >>= 1) {
      if(l & 1) L = f(L, reflect(l++));
      if(r & 1) R = f(reflect(--r), R);
    }
    return f(L, R);
  }

  Monoid operator[](const int &k) {
    return query(k, k + 1);
  }

  template< typename C >
  int find_subtree(int a, const C &check, Monoid &M, bool type) {
    while(a < sz) {
      propagate(a);
      Monoid nxt = type ? f(reflect(2 * a + type), M) : f(M, reflect(2 * a + type));
      if(check(nxt)) a = 2 * a + type;
      else M = nxt, a = 2 * a + 1 - type;
    }
    return a - sz;
  }

  template< typename C >
  int find_first(int a, const C &check) {
    Monoid L = M1;
    if(a <= 0) {
      if(check(f(L, reflect(1)))) return find_subtree(1, check, L, false);
      return -1;
    }
    thrust(a + sz);
    int b = sz;
    for(a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
      if(a & 1) {
        Monoid nxt = f(L, reflect(a));
        if(check(nxt)) return find_subtree(a, check, L, false);
        L = nxt;
        ++a;
      }
    }
    return -1;
  }


  template< typename C >
  int find_last(int b, const C &check) {
    Monoid R = M1;
    if(b >= sz) {
      if(check(f(reflect(1), R))) return find_subtree(1, check, R, true);
      return -1;
    }
    thrust(b + sz - 1);
    int a = sz;
    for(b += sz; a < b; a >>= 1, b >>= 1) {
      if(b & 1) {
        Monoid nxt = f(reflect(--b), R);
        if(check(nxt)) return find_subtree(b, check, R, true);
        R = nxt;
      }
    }
    return -1;
  }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll N, K, M;
    cin >> N >> K >> M;
    vl A(N);
    REP(i, N) cin >> A[i];

    auto f = [](ll x, ll y){return max(x, y);};
    auto g = [](ll x, ll a){return x+a;};
    auto h = [](ll a, ll b){return a+b;};
    ll M1 = -(1ll<<60);
    ll OM0 = 0;
    vector<LazySegmentTree<ll, ll, decltype(f), decltype(g), decltype(h)>> seg1(2, LazySegmentTree<ll, ll, decltype(f), decltype(g), decltype(h)>(N+1, f, g, h, M1, OM0));
    vector<LazySegmentTree<ll, ll, decltype(f), decltype(g), decltype(h)>> seg2(2, LazySegmentTree<ll, ll, decltype(f), decltype(g), decltype(h)>(N+1, f, g, h, M1, OM0));

    auto val_update1 = [&](ll n, ll k, ll val){
        ll tmp = seg1[n%2][k];
        seg1[n%2].update(k, k+1, val-tmp);
    };

    auto val_update2 = [&](ll n, ll k, ll val){
        ll tmp = seg2[n%2][k];
        seg2[n%2].update(k, k+1, val-tmp);
    };

    val_update1(0, 0, 0);
    val_update2(0, 0, 0);

    REP(k, K){
        ll nk = (k+1)%2;
        // REP(i, N) seg1[nk].set(i, M1);
        // REP(i, N) seg2[nk].set(i, M1);
        // seg1[nk].build();
        // seg2[nk].build();
        REP(i, N+1) val_update1(nk, i, M1);
        REP(i, N+1) val_update2(nk, i, M1);
        REP(i, N){
            seg1[k%2].update(0, i+1, A[i]);
            seg2[k%2].update(0, i+1, -A[i]);
            ll val = 0;
            ll left = max(i-M+1, 0ll);
            chmax(val, seg1[k%2].query(left, i+1));
            chmax(val, seg2[k%2].query(left, i+1));
            val_update1(nk, i+1, val);
            val_update2(nk, i+1, val);
        }
    }

    ll res = seg1[K%2][N];

    cout << res << endl;

    return 0;
}