#include<iostream>

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;

constexpr int MAX = 3100;
	
int dp[MAX][2];
int sum[MAX];
static int qf[MAX], q2f[MAX];
static int qs[MAX], q2s[MAX];
pair<int,int> q[MAX], q2[MAX];

signed main(){
	int N, K, M, A;
	

	
	cin>>N>>K>>M;
	
	sum[0] = 0;
	
	for(int i = 0; i < N; i++){
		cin>>A;
	
		sum[i+1] = sum[i] + A;
		
		if(i < M) dp[i][1] = abs(sum[i+1]);
	}

	for(int j = 2, k = 0; j <= K; j++, k = !k){
		int f = 0, e = 0, f2 = 0, e2 = 0;
		int L = min(N, M * (j));
		
		for(int i = j-1; i < L; i++){
			int num = dp[i-1][!k] - sum[i];
			int num2 = dp[i-1][!k] + sum[i];
			
			while(e - f && qs[e-1] < num) e--;
			qf[e] = i;
			qs[e] = num;
			e++;
			while(e - f && qf[f] < i - M + 1) f++;
			
			while(e2 - f2 && q2s[e2-1] < num2) e2--;
			q2f[e2] = i;
			q2s[e2] = num2;
			e2++;
			while(e2 - f2 && q2f[f2] < i - M + 1) f2++;
			
			dp[i][k] = max(qs[f] + sum[i+1], q2s[f2]  - sum[i+1]);
		}
	}
	
	cout<<dp[N-1][K%2]<<endl;
	
	return 0;
}