ll x[300000];
ll pref[300000];
int main(){
	ll n, a, b;
	cin>>n>>a>>b;
    x[0]=pref[0]=0;
	for(ll i=1;i<=n;i++){
		cin>>x[i];
	}
	multiset<ll> cur;
	pref[1]=x[1];
	for(ll i=1;i<=n;i++){
		pref[i]=pref[i-1]+x[i];
	}
    ll ans=-2e18;
    for(int i=a;i<=n;i++){
       // dbg(i);
        cur.insert(pref[i-a]);
        if(i>b){
            //erase
            if(cur.find(pref[i-b-1])!=cur.end())
            cur.erase(cur.find(pref[i-b-1]));
        }
        ans=max(ans, pref[i]-*cur.begin());
    }

    cout<<ans<<'\n';
}