#include <bits/stdc++.h>
using namespace std;
#define modulo 1000000007
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 1000000000000000000

template <typename T,typename F>
struct SWAG{
	F func;
	T init_value;
	vector<pair<T,T>> X,Y;
	SWAG(F f,T iv):func(f){
		init_value = iv;
	}
	
	void push_front(T x){
		if(X.empty())X.push_back({x,x});
		else X.push_back({x,func(x,X.back().second)});
	}
	
	void push_back(T x){
		if(Y.empty())Y.push_back({x,x});
		else Y.push_back({x,func(Y.back().second,x)});
	}
	
	void pop_front(){
		if(X.empty()){
			int n = Y.size();
			vector<T> t;
			for(int i=0;i<n/2;i++){
				t.push_back(Y.back().first);
				Y.pop_back();
			}
			while(!Y.empty()){
				push_front(Y.back().first);
				Y.pop_back();
			}
			while(!t.empty()){
				push_back(t.back());
				t.pop_back();
			}
			if(!X.empty())X.pop_back();
		}
		else{
			X.pop_back();
		}
	}
	
	void pop_back(){
		if(Y.empty()){
			int n = X.size();
			vector<T> t;
			for(int i=0;i<n/2;i++){
				t.push_back(X.back().first);
				X.pop_back();
			}
			while(!X.empty()){
				push_back(X.back().first);
				X.pop_back();
			}
			while(!t.empty()){
				push_front(t.back());
				t.pop_back();
			}
			if(!Y.empty())Y.pop_back();
		}
		else{
			Y.pop_back();
		}
	}
	
	T get(){
		T ret = init_value;
		if(!X.empty())ret = func(ret,X.back().second);
		if(!Y.empty())ret = func(ret,Y.back().second);
		return ret;
	}
	
	T front(){
		if(!X.empty())return X.back().first;
		if(!Y.empty())return Y[0].first;
		return init_value;
	}
	
	T back(){
		if(!Y.empty())return Y.back().first;
		if(!X.empty())return X[0].first;
		return init_value;
	}
	
	int size(){
		return X.size()+Y.size();
	}
	
};

int main(){
	int N,K,M;
	cin>>N>>K>>M;
	vector<long long> A(N);
	for(int i=0;i<N;i++)cin>>A[i];
	/*
N=3000,M=3000,K=3000;
A.resize(N,3);
*/
	vector<long long> S(N+1,0);
	for(int i=1;i<=N;i++){
		S[i] = S[i-1] + A[i-1];
	}
	
	auto f = [](pair<long long,int> a,pair<long long,int> b){
		return max(a,b);
	};
	
	vector<SWAG<pair<long long,int>,decltype(f)>> Sm(K+1,SWAG<pair<long long,int>,decltype(f)>(f,make_pair(-Inf,0))),
	Sp(K+1,SWAG<pair<long long,int>,decltype(f)>(f,make_pair(-Inf,0)));

	
	vector<long long> dp(K+1,-Inf);
	dp[0] = 0LL;
	Sm[0].push_back(make_pair(0LL,0));
	Sp[0].push_back(make_pair(0LL,0));
	
	for(int i=1;i<=N;i++){
		vector<long long> ndp(K+1,-Inf);
		for(int j=1;j<=K;j++){
			
			if(Sm[j-1].size()!=0&&Sm[j-1].front().second+M<i){
				Sm[j-1].pop_front();
			}
			if(Sp[j-1].size()!=0&&Sp[j-1].front().second+M<i){
				Sp[j-1].pop_front();
			}
			

			ndp[j] = max(Sm[j-1].get().first + S[i],Sp[j-1].get().first - S[i]);
		}
		for(int j=1;j<=K;j++){
			if(ndp[j]<0)continue;
			while(true){
				if(Sm[j].size()==0)break;
				if(Sm[j].back().first<=ndp[j]-S[i]){
					Sm[j].pop_back();
				}
				else break;
			}
			while(true){
				if(Sp[j].size()==0)break;
				if(Sp[j].back().first<=ndp[j]+S[i]){
					Sp[j].pop_back();
				}
				else break;
			}
			Sm[j].push_back(make_pair(ndp[j]-S[i],i));
			Sp[j].push_back(make_pair(ndp[j]+S[i],i));
		}
		swap(dp,ndp);
	}
	
	cout<<dp.back()<<endl;
	
	return 0;
}