#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<utility>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1'000'000'007; 

// struct fast_io {
	// fast_io(){
		// std::cin.tie(nullptr);
		// std::ios::sync_with_stdio(false);
	// };
// } fio;


template<typename T>
class lazy_segment_tree{
	int n;
	T fval;
	vector<T> dat, lazy;
	
public:
	
	lazy_segment_tree(){
		
	}
	
	lazy_segment_tree(int n_, T val){
		init(n_, val);
	}
	
	~lazy_segment_tree(){
		
	}
	
	void init(int n_, T val){
		fval = val;
		
		n = 1;
		
		while(n < n_) n *= 2;
		
		dat.resize(2 * n - 1);
		lazy.resize(2 * n - 1, fval);
	
		for(int i = 0; i < 2 * n - 1; i++) dat[i] = fval;
	}
	
	void eval(int k, int l, int r){
		
		if(lazy[k] != fval){
			dat[k] = dat[k] + lazy[k]/(r - l);
			
			if(r - l > 1) {
				lazy[2*k+1] = lazy[2*k+1] + lazy[k]/2;
				lazy[2*k+2] = lazy[2*k+2] + lazy[k]/2;
			}
			
			lazy[k] = 0;
		}
	}
	
	void update(int a, int b, T x, int k = 0, int l = 0, int r = -1){
		if(r < 0) r = n;
		eval(k, l, r);
		if(b <= l || r <= a) {return ;}
		if(a <= l && r <= b){
			lazy[k] = lazy[k] + (r - l) * x;
			eval(k, l, r);
		} else {
			update(a, b, x, 2*k+1, l, (l+r)/2);
			update(a, b, x, 2*k+2, (l+r)/2, r);
			dat[k] = max(dat[2*k+1], dat[2*k+2]);
		}
	}
	
	T query(int a, int b, int k = 0, int l = 0, int r = -1){
		if(r < 0) r = n;
		eval(k, l, r);
		if(r <= a || b <= l){
			return -INF;
		}
		if(a <= l && r <= b){
			return dat[k];
		}else {
			T vl = query(a, b, k * 2 + 1, l, (l + r) / 2 );
			T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
			return max(vl, vr);
		}
	}
};


signed main(){
	cout<<fixed<<setprecision(10);
	
	int N, K, M;
	vector<int> A;
	vector<int> sum;
	vector<vector<int>> dp;
	
	cin>>N>>K>>M;
	
	A.resize(N);
	dp.resize(N+1, vector<int>(K+1, -INF));
	sum.resize(N+1);
	
	for(int i = 0; i < N; i++){
		cin>>A[i];
	
		sum[i+1] = sum[i] + A[i];
		
		if(i < M) dp[i][1] = abs(sum[i+1]);
	}
	
	for(int j = 2; j <= K; j++){
		lazy_segment_tree<int> lseg, lseg2;
		
		
		lseg.init(N+2, 0);
		lseg2.init(N+2, 0);
		
		for(int i = 0; i < N; i++){
			lseg.update(i, i+1, dp[i][j-1]);
			lseg2.update(i, i+1, dp[i][j-1]);
		}
	
		for(int i = j-1; i < N; i++){
			lseg.update(j-2, i, A[i]);
			lseg2.update(j-2, i, -A[i]);
			
			
			dp[i][j] = max(-INF, max(lseg.query(max(j-2, i - M), i), lseg2.query(max(j-2, i - M), i)));
		}
	}
	
	cout<<dp[N-1][K]<<endl;
	
	return 0;
}