// dp solution just so i can see if its correct
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
#include <cstring>
int x, p, q;
std::vector<int> arr;
std::vector<std::vector<std::vector<char>>> dp;
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) {
dp.assign(x,std::vector<std::vector<char>>(p+1,std::vector<char>(q+1,-1)));
return sol(0,0,0,cap);
}
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);
}
