#include <bits/stdc++.h>
using namespace std;

const int N =  100010;

long long ans,n,s,t,a[N],sum[N];

deque <long long> q;

int main(){
	freopen("ggame.in",r,stdin);
	freopen("ggame.out",w,stdout); 
	scanf("%lld%lld%lld",&n,&s,&t);
	for(int i=1;i<=n;i++){
		scanf("%lld",&a[i]);
		sum[i]=sum[i-1]+a[i];
	}
	for(int i=s;i<=n;i++){
		while(q.size()&&sum[q.back()]>=sum[i-s])q.pop_back();
		q.push_back(i-s);
		while(q.front()<i-t)q.pop_front();
		ans=max(ans,sum[i]-sum[q.front()]);
	}
	printf("%lld",ans);
	return 0;
}