// Finally WSL
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
#define all(x) (x).begin(), (x).end()
#define isz(x) (int)x.size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
void run(int tc) {
int n, p, q;
cin >> n >> p >> q;
// n <= 2000, fool!
p = min(n, p);
q = min(n, q);
vector<int> a(n + 1);
for (int i = 1; i <= n; i++) cin >> a[i];
sort(a.begin() + 1, a.end());
long long low = 1, high = 1e9, best = 1e18;
auto check = [&](long long w) -> bool {
vector<array<int, 2>> nxt(n + 1);
for (int i = 1; i <= n; i++) {
auto it = upper_bound(a.begin() + i, a.end(), a[i] + w - 1);
nxt[i][0] = (it - 1) - a.begin();
it = upper_bound(a.begin() + i, a.end(), a[i] + 2 * w - 1);
nxt[i][1] = (it - 1) - a.begin();
}
debug(nxt);
vector<vector<int>> dp(p + 1, vector<int>(q + 1, 0));
for (int small = 0; small <= p; small++) {
for (int big = 0; big <= q; big++) {
if (dp[small][big] == -1) continue;
int idx = dp[small][big];
if (small < p) dp[small + 1][big] = max({dp[small + 1][big], dp[small][big], nxt[idx + 1][0]});
if (big < q) dp[small][big + 1] = max({dp[small][big + 1], nxt[idx + 1][1], dp[small][big]});
}
}
debug(dp[p][q]);
return dp[p][q] >= n;
};
while (low <= high) {
long long mid = (low + high) >> 1;
if (check(mid)) {
high = mid - 1;
best = mid;
} else {
low = mid + 1;
}
}
cout << best << endl;
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
for (int tc = 1; tc <= t; tc++) run(tc);
}
