#include <algorithm>
#include <array>
#include <cassert>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <vector>
using namespace std;
using int64 = int64_t;
using ld = long double;
template<typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using max_heap = priority_queue<T, vector<T>, less<T>>;
[[maybe_unused]] int readInt() {
int x;
cin >> x;
return x;
}
[[maybe_unused]] int64 readInt64() {
int64 x;
cin >> x;
return x;
}
[[maybe_unused]] char readChar() {
char c;
cin >> c;
return c;
}
[[maybe_unused]] string readString() {
string s;
cin >> s;
return s;
}
[[maybe_unused]] double readDouble() {
return stod(readString());
}
[[maybe_unused]] ld readLongDouble() {
return stold(readString());
}
template<typename T1, typename T2>
[[maybe_unused]] pair<T1, T2> readPair() {
pair<T1, T2> p;
cin >> p.first >> p.second;
return p;
}
template<typename T>
[[maybe_unused]] vector<T> readVec(const int sz) {
vector<T> v(sz);
for (T &x : v) {
cin >> x;
}
return v;
}
template<typename T>
[[maybe_unused]] vector<vector<T>> readVecVec(const int n, const int m) {
vector<vector<T>> a(n);
for (vector<T> &v : a) {
v = readVec<T>(m);
}
return a;
}
const int64 kInf64 = 2e18 + 10;
const int kInf = 2e9 + 10;
const int kMod = 1e9 + 7;
void solution() {
const int n = readInt(), p = min(n, readInt()), q = min(n, readInt());
vector<int> a(n + 1, -kInf);
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
sort(a.begin(), a.end());
vector<vector<int>> dp(n + 1, vector<int>(p + 1));
auto check = [&](const int w) {
for (int i = 0; i <= p; i++) dp[0][i] = 0;
queue<int> last_p, last_q;
last_p.push(0), last_q.push(0);
for (int i = 1; i <= n; i++) {
last_p.push(i), last_q.push(i);
while (a[last_p.front()] <= a[i] - w) {
last_p.pop();
}
while (a[last_q.front()] <= a[i] - 2 * w) {
last_q.pop();
}
const int lp = last_p.front(), lq = last_q.front();
dp[i][0] = dp[lq - 1][0] + 1;
for (int j = 1; j <= p; j++) {
const int op1 = dp[lp - 1][j - 1];
const int op2 = dp[lq - 1][j] + 1;
dp[i][j] = min(op1, op2);
}
}
return (dp[n][p] <= q);
};
int lo = 1, hi = 1e9;
while (lo < hi) {
const int mid = (lo + hi) / 2;
if (check(mid)) {
hi = mid;
} else {
lo = mid + 1;
}
}
cout << lo << '\n';
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
const auto begin = std::chrono::high_resolution_clock::now();
// freopen(".in", "r", stdin);
// freopen(".out", "w", stdout);
int t = 1;
//cin >> t;
for (int tc = 1; tc <= t; tc++) {
solution();
}
const auto end = std::chrono::high_resolution_clock::now();
const auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";
}
