/**
* Author: Qardashali
**/
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAXN = 2005;
int n, p, q;
int a[MAXN];
int next_s[MAXN], next_l[MAXN];
int dp[MAXN][MAXN];
bool check(int w){
int ps = 0, pl = 0;
for(int i = 0; i < n; i++){
while(ps < n && a[ps] < (ll)a[i] + w){
ps++;
}
next_s[i] = ps;
while(pl < n && a[pl] < (ll)a[i] + 2LL * w){
pl++;
}
next_l[i] = pl;
}
next_s[n] = n;
next_l[n] = n;
int lp = min(p, n);
int lq = min(q, n);
for(int i = 0; i <= lp; i++){
for(int j = 0; j <= lq; j++){
dp[i][j] = 0;
}
}
for(int i = 0; i <= lp; i++){
for(int j = 0; j <= lq; j++){
if(i + j > n){
break;
}
int cur = dp[i][j];
if(cur == n){
return true;
}
if(i < lp){
if(next_s[cur] > dp[i + 1][j]){
dp[i + 1][j] = next_s[cur];
}
}
if(j < lq){
if(next_l[cur] > dp[i][j + 1]){
dp[i][j + 1] = next_l[cur];
}
}
}
}
return false;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> p >> q;
for(int i = 0; i < n; i++){
cin >> a[i];
}
sort(a, a + n);
if(p + q >= n){
cout << 1 << '\n';
return 0;
}
int l = 1, h = 1000000000, ans = 1000000000;
while(l <= h){
int mid = l + (h - l) / 2;
if(check(mid)){
ans = mid;
h = mid - 1;
}
else{
l = mid + 1;
}
}
cout << ans << '\n';
return 0;
}
