#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;

template<typename T1,typename T2>
ostream &operator<<(ostream &os,const pair<T1,T2>&p){
    os<<p.first<<" "<<p.second;
    return os;
}

template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==v.size()?"":" ");
    return os;
}

// Semigroup Sliding-Window-AGregation
template<typename Semigroup>
struct SWAG{
    using F=function<Semigroup(Semigroup,Semigroup)>;
    const F f;
    stack<pair<Semigroup,Semigroup>> fr,ba;
    SWAG(const F f):f(f){}
    Semigroup get(){
        if(fr.empty()) return ba.top().second;
        if(ba.empty()) return fr.top().second;
        return f(fr.top().second,ba.top().second);
    }
    void push(Semigroup x){
        if(ba.empty()) ba.push(make_pair(x,x));
        else ba.push(make_pair(x,f(ba.top().second,x)));
    }
    void pop(){
        if(empty()) return ;
        if(!fr.empty()) fr.pop();
        else{
            while(!ba.empty()){
                pair<Semigroup,Semigroup> p=ba.top();ba.pop();
                if(fr.empty()) fr.push(make_pair(p.first,p.first));
                else fr.push(make_pair(p.first,f(p.first,fr.top().second)));
            }
            fr.pop();
        }
    }
    size_t size(){
        return fr.size()+ba.size();
    }
    bool empty(){
        return size()==0;
    }
};

ll dp[3010][3010],a[3010],sum[3010];

signed main(){
    rep(i,3010)rep(j,3010)dp[i][j]=-LINF;
    dp[0][0]=0;
    
    int n,k,m;cin>>n>>k>>m;
    rep(i,n){
        cin>>a[i];
        sum[i+1]=sum[i]+a[i];
    }

    auto f=[](ll a,ll b){return a>b?a:b;};
    rep(j,k){
        SWAG<ll> s1(f),s2(f);
        rep(i,n){
            if(s1.size()>=m) s1.pop();
            if(s2.size()>=m) s2.pop();
            s1.push(dp[i][j]-sum[i]);
            s2.push(dp[i][j]+sum[i]);

            chmax(dp[i+1][j+1],s1.get()+sum[i+1]);
            chmax(dp[i+1][j+1],s2.get()-sum[i+1]);
        }
    }
    
    cout<<dp[n][k]<<endl;
    return 0;
}