#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
#include <cstring>
int x, p, q;
std::vector<int> arr;
char dp[101][101][101];
char sol(int pos, int a, int b, int cap) {
if (a>p||b>q) {
return 0;
}
if (pos==x) {
return 1;
}
if (dp[pos][a][b]!=-1) {
return dp[pos][a][b];
}
char ret = 0;
for (int i = pos; i < x; i++) {
if (arr[i]-arr[pos]+1 <= cap) {
ret |= sol(i+1,a+1,b,cap);
}
if (arr[i]-arr[pos]+1 <= 2*cap) {
ret |= sol(i+1,a,b+1,cap);
}
}
return dp[pos][a][b] = ret;
}
bool can_solve(int cap, bool debug = 0) {
if (x<=100) {
memset(dp,-1,sizeof(dp));
return sol(0,0,0,cap);
}
else {
std::vector<int> tmp = arr;
if (debug) {
for (const auto& i : tmp) {
std::cout << i << " ";
}
std::cout << "\n";
}
// first use the large cameras
for (int iterations = 0; iterations < q && !tmp.empty(); iterations++) {
int w = 2*cap;
int max = -1, max_l = -1, max_r = -1;
for (int l = 0, r = 0; r < tmp.size(); r++) {
while (tmp[r]-tmp[l]+1 > w) {
++l;
}
if (r-l+1>max) {
max = r-l+1;
max_l = l;
max_r = r;
}
}
tmp.erase(tmp.begin()+max_l,tmp.begin()+max_r+1);
if (debug) {
std::cout << max_l << " " << max_r << "\n";
for (const auto& i : tmp) {
std::cout << i << " ";
}
std::cout << "\n";
}
}
// then the small cameras
for (int iterations = 0; iterations < p && !tmp.empty(); iterations++) {
int w = cap;
int max = -1, max_l = -1, max_r = -1;
for (int l = 0, r = 0; r < tmp.size(); r++) {
while (tmp[r]-tmp[l]+1 > w) {
++l;
}
if (r-l+1>max) {
max = r-l+1;
max_l = l;
max_r = r;
}
}
tmp.erase(tmp.begin()+max_l,tmp.begin()+max_r+1);
if (debug) {
std::cout << max_l << " " << max_r << "\n";
for (const auto& i : tmp) {
std::cout << i << " ";
}
std::cout << "\n";
}
}
return tmp.empty();
}
}
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(NULL);
std::cout.tie(NULL);
std::cin >> x >> p >> q;
// we only need at most x cameras in total, out of which we'll greedily take as many big cameras as possible
if (p+q>x) {
q = std::min(q, x);
p = x-q;
}
for (int i = 0, tmp; i < x; i++) {
std::cin >> tmp;
arr.emplace_back(tmp);
}
std::sort(arr.begin(),arr.end());
const auto bs = [&]() {
int ret = 1000000001;
int l = 1, r = 1000000000;
while (l<=r) {
int m = (l+r)>>1;
if (can_solve(m)) {
ret = m;
r = m-1;
}
else {
l = m+1;
}
}
return ret;
};
std::cout << bs() << "\n";
//can_solve(bs(),1);
}
