#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define fi first
#define in inline
#define se second
#define mp make_pair
#define pb push_back
const int N = 1e5+10;
const ll inf = 1e18;

ll read(){
	ll x = 0,f = 1;char c = getchar();
	for(;c < '0' || c > '9';c = getchar())if(c == '-')f = -1;
	for(;c >= '0' && c <= '9';c = getchar())x = (x<<1) + (x<<3) + c-'0';
	return x * f;
}


int n,s,t; 
ll a[N],ans = -inf;
int st[N],l = 1,r;
int main(){
	freopen("ggame.in","r",stdin);
	freopen("ggame.out","w",stdout);
	n = read(),s = read(),t = read();
	for(int i = 1;i <= n;i++)a[i] = read() + a[i-1];
	for(int i = 1;i <= n;i++){
		while(l <= r && st[l] < i - t)l++;
		if(l <= r)ans = max(ans,a[i] - a[st[l]]);
		if(i >= s){
			while(l <= r && a[st[r]] >= a[i-s])r--;
			st[++r] = i - s;
		}
	}
	printf("%lld\n",ans);

	return 0;

}