#include <iostream>
#include <string>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <unordered_map>
#include <map>
#include <set>
#include <algorithm>
#include <queue>
#include <stack>
#include <functional>
#include <bitset>
#include <assert.h>
#include <unordered_map>
#include <fstream>
#include <time.h>
#include <deque>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef pair<ll,ll> P;
typedef pair<int,int> pii;
typedef vector<P> vpl;
typedef tuple<ll,ll,ll> tapu;
#define rep(i,n) for(int i=0; i<(n); i++)
#define REP(i,a,b) for(int i=(a); i<(b); i++)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const int inf = 1<<30;
const ll linf = 1LL<<62;
const int MAX = 2020000;
ll dy[8] = {1,-1,0,0,1,-1,1,-1};
ll dx[8] = {0,0,1,-1,1,-1,-1,1};
const double pi = acos(-1);
const double eps = 1e-7;
template<typename T1,typename T2> inline bool chmin(T1 &a,T2 b){
	if(a>b){
		a = b; return true;
	}
	else return false;
}
template<typename T1,typename T2> inline bool chmax(T1 &a,T2 b){
	if(a<b){
		a = b; return true;
	}
	else return false;
}
template<typename T> inline void print(T &a){
    rep(i,a.size()) cout << a[i] << " ";
    cout << "\n";
}
template<typename T1,typename T2> inline void print2(T1 a, T2 b){cout << a << " " << b << "\n";}
template<typename T1,typename T2,typename T3> inline void print3(T1 a, T2 b, T3 c){
	cout << a << " " << b << " " << c << "\n";
}
const int mod = 1e9 + 7;
//const int mod = 998244353;

int main(){
	ll n,k,m; cin >> n >> k >> m;
    vl a(n); rep(i,n) cin >> a[i];
    vl s(n+1,0); rep(i,n) s[i+1] = s[i] + a[i];
    vvl dp(2,vl(k+2,-linf));
    vector<deque<P>> d1(k+1), d2(k+1);
    d1[0].emplace_back(s[0],0);
    d2[0].emplace_back(-s[0],0);
    REP(j,1,k+1){
        d1[j].emplace_back(-linf,0);
        d2[j].emplace_back(-linf,0);
    }
    dp[0][0] = 0;
    rep(i,n){
        rep(j,k+1) dp[1][j] = -linf;
        rep(j,k+1){
            chmax(dp[1][j+1], d1[j].front().first - s[i+1]);
            chmax(dp[1][j+1], d2[j].front().first + s[i+1]);
            while(!d1[j].empty()){
                ll t = d1[j].back().first;
                if(t <= dp[1][j] + s[i+1]) d1[j].pop_back();
                else break;
            }
            while(!d2[j].empty()){
                ll t = d2[j].back().first;
                if(t <= dp[1][j] - s[i+1]) d2[j].pop_back();
                else break;
            }
            d1[j].emplace_back(dp[1][j] + s[i+1], i+1);
            d2[j].emplace_back(dp[1][j] - s[i+1], i+1);
            while(d1[j].front().second <= i-m+1) d1[j].pop_front();
            while(d2[j].front().second <= i-m+1) d2[j].pop_front();
        }
        swap(dp[0], dp[1]);
    }
    cout << dp[0][k] << "\n";
}