#include <iostream>
#include <vector>
#include <set>
#include <climits>
using namespace std;
 
int main() {
 
	long long n,a,b;
	cin>>n>>a>>b;
 
	vector<long long> V;
	for(long long i=0;i<n;i++)
	{
		long long x;
		cin>>x;
		V.push_back(x);
	}
	long long prefixSum[n+1];
	prefixSum[0]=0;
	for(long long i=1;i<=n;i++)
	{
		prefixSum[i] = prefixSum[i-1]+V[i-1];
	}
	multiset<long long> ms;
	for(long long i=a;i<=b;i++)
	{
		ms.insert(prefixSum[i]);
	}
 
	long long maxSum = LLONG_MIN;
	for(long long i=1;i<=n-a+1;i++)
	{
		maxSum = max(maxSum,*ms.rbegin() - prefixSum[i-1]);
		ms.erase(ms.find(prefixSum[i+a-1]));
		if(i+b <= n)
		{
			ms.insert(prefixSum[i+b]);
		}
		//cout<<"maxSum="<<maxSum<<" ms.size()="<<ms.size()<<endl;
	}
 
	cout<<maxSum<<endl;
 
	return 0;
}

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MTAgMSAzCjAgMSAwIDAgMCAxIDEgMiAwIDA=

10 1 3
0 1 0 0 0 1 1 2 0 0