// File C.cpp created on 03.08.2025 at 14:29:34
#include <bits/stdc++.h>
using i64 = long long;
#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) void(23)
#endif
bool chmax(int& a, int b) {
if (a < b) {
a = b;
return true;
}
return false;
}
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
int N, P, Q;
std::cin >> N >> P >> Q;
std::vector<int> A(N);
for (int i = 0; i < N; ++i) {
std::cin >> A[i];
}
std::sort(A.begin(), A.end());
P = std::min(P, N);
Q = std::min(Q, N);
std::vector<std::vector<int>> f;
auto check = [&](int w) -> int {
f.assign(P + 1, std::vector<int>(Q + 1));
for (int i = 0; i <= P; ++i) {
for (int j = 0; j <= Q; ++j) {
if (f[i][j] == N) {
return true;
}
int x = f[i][j];
if (i != P) {
int y = int(std::lower_bound(A.begin(), A.end(), A[x] + w) - A.begin());
chmax(f[i + 1][j], y);
}
if (j != Q) {
int y = int(std::lower_bound(A.begin(), A.end(), A[x] + 2 * w) - A.begin());
chmax(f[i][j + 1], y);
}
}
}
return false;
};
int lo = 1, hi = A.back();
while (lo < hi) {
int mid = (lo + hi) >> 1;
if (check(mid)) {
hi = mid;
} else {
lo = mid + 1;
}
}
std::cout << lo << '\n';
return 0;
}
