rt， 此代码非Hack点全A

#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
int a[maxn], dp[maxn];
int main() {
	int n, l, r;
	cin >> n >> l >> r;
	for (int i = 1; i <= n; i++) dp[i] = -2e9;
	cin >> a[0];
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	for (int i = 0; i <= n; i++) {
		for (int j = l; j <= r; j++) {
			if (i + j > n) dp[n + 1] = max(dp[n + 1], dp[i]);
			else {
				dp[i + j] = max(dp[i] + a[i + j], dp[i + j]);
			}
		}
	}
	cout << dp[n + 1] << endl;
}