#include <bits/stdc++.h>
using namespace std;
#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()
#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define debug(...) "[" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
template <class A, class B> bool minimize(A &a, B b) { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b) { if (a < b) { a = b; return true; } return false; }
const int MAXN = 1e5 + 5;
const long long INF = 1e18;
long long findMaxAttraction(int n, int start, int d, int A[]) {
auto sub2 = [&] () -> long long {
long long ans = 0, sum = 0;
priority_queue <int, vector <int>, greater <int>> q;
for (int i = 0; i < n; ++i) {
q.push(A[i]);
sum += A[i];
while((int) q.size() > max(0, d - i)) {
sum -= q.top(); q.pop();
}
maximize(ans, sum);
}
return ans;
};
auto sub3 = [&]() -> long long {
long long ans = 0;
for (int i = start; i < n; ++i) {
priority_queue <int, vector <int>, greater <int>> q;
long long sum = 0;
for (int j = start; j <= i; ++j) {
q.push(A[j]); sum += A[j];
while((int) q.size() > max(0, d - 2 * (j - start))) {
sum -= q.top(); q.pop();
}
}
for(int j = start - 1; j >= 0; --j) {
q.push(A[j]); sum += A[j];
while((int) q.size() > max(0, d - 2 * (i - start) - (start - j))) {
sum -= q.top(); q.pop();
}
maximize(ans, sum);
}
}
for (int i = start; i >= 0; --i) {
priority_queue <int, vector <int>, greater <int>> q;
long long sum = 0;
for (int j = start; j >= i; --j) {
q.push(A[j]); sum += A[j];
while((int) q.size() > max(0, d - 2 * (start - j))) {
sum -= q.top(); q.pop();
}
}
for (int j = start + 1; j < n; ++j) {
q.push(A[j]); sum += A[j];
while((int) q.size() > max(0, d - 2 * (start - i) - (j - start))) {
sum -= q.top(); q.pop();
}
maximize(ans, sum);
}
}
return ans;
};
if(start == 0) return sub2();
if(n <= 3000) return sub3();
}
#ifdef LOCAL
#include<cstdio>
int main() {
freopen("TASK.inp", "r", stdin);
freopen("TASK.out", "w", stdout);
int n, start, d;
int attraction[100000];
int i, n_s;
n_s = scanf("%d %d %d", &n, &start, &d);
for (i = 0 ; i < n; ++i) {
n_s = scanf("%d", &attraction[i]);
}
printf("%lld\n", findMaxAttraction(n, start, d, attraction));
return 0;
}
#endif // LOCAL
// Dream it. Wish it. Do it.
