#include<bits/stdc++.h>
using namespace std;
using LL=long long;
using ULL=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

const LL INF=1000000000000000;

int N,K,M;
LL A[2][3001];
LL dp[2][3001][3001];
deque<int> dpw[2][3001];

int main(){
	cin>>N>>K>>M;
	rep(i,N) cin>>A[0][i]; A[0][N]=0;
	for(int i=N-1; i>=0; i--) A[0][i]+=A[0][i+1];
	rep(i,N+1) A[1][i]=-A[0][i];

	rep(t,2) rep(i,N+1) rep(k,K+1) dp[t][k][i]=-INF;
	rep(t,2) dp[t][0][0]=A[t][0];
	rep(t,2) rep(k,K+1) dpw[t][k]={0};

	rep(i,N) rep(k,K){
		LL tmp = -INF;
		rep(t,2){
			if(dpw[t][k].size()) if(dpw[t][k].front()<=i-M) dpw[t][k].pop_front();
			if(dpw[t][k].size()) tmp=max(tmp,dp[t][k][dpw[t][k].front()]-A[t][i+1]);
		}
		rep(t,2){
			dp[t][k+1][i+1]=tmp+A[t][i+1];
			while(dpw[t][k+1].size()) if(dp[t][k+1][dpw[t][k+1].back()]<=dp[t][k+1][i+1]) dpw[t][k+1].pop_back(); else break;
			dpw[t][k+1].push_back(i+1);
		}
	}

	cout<<dp[0][K][N]<<endl;

	return 0;
}