#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
int n, p, q;
cin >> n >> p >> q;
vector<ll> a(n + 1);
for(int i = 1; i <= n; i++) cin >> a[i];
sort(a.begin() + 1, a.end());
p = min(p, n);
q = min(q, n);
auto good = [&](ll k){
vector<vector<int>> dp(p + 1, vector<int>(q + 1, 0));
for(int i = 0; i <= p; i++){
for(int j = 0; j <= q; j++){
int s = dp[i][j] + 1;
if(s > n) return true;
if(i < p){
int pos = s;
while(pos <= n && a[pos] - a[s] < k) pos++;
dp[i + 1][j] = max(dp[i + 1][j], pos - 1);
}
if(j < q){
int pos = s;
while(pos <= n && a[pos] - a[s] < 2 * k) pos++;
dp[i][j + 1] = max(dp[i][j + 1], pos - 1);
}
}
}
return false;
};
ll l = 0, r = 1e9 + 1;
while(l + 1 < r){
ll mid = (l + r) >> 1;
if(good(mid)) r = mid;
else l = mid;
}
cout << r << '\n';
}
