#include <bits/stdc++.h>
using namespace std;
int main(){
int n, p, q;
cin >> n >> p >> q;
if(p + q >= n) {
cout <<"1\n";
return 0;
}
vector<int> a(n);
for(int&A:a) cin >> A;
sort(a.begin(), a.end());
int lo = 1, hi = 1e9;
while(lo <= hi){
int mid = (lo + hi) / 2;
vector<vector<int>> dp(n + 1, vector<int>(n + 1, -(1)));
vector<int> P(n + 1), Q(n + 1);
//cerr << "HERE\n";
for(int i=0; i < n; i++){
P[i] = (lower_bound(a.begin(), a.end(), a[i] + mid) - a.begin()) - i;
//cerr << "P " << P[i] << endl;
}
for(int i=0; i < n; i++){
Q[i] = (lower_bound(a.begin(), a.end(), a[i] + mid * 2) - a.begin()) - i;
//cerr << "Q " << Q[i] << endl;
}
dp[0][0] = 0;
bool good = 0;
for(int i=0; i <= p; i++){
for(int j=0; j <= q; j++){
if(dp[i][j] == n){
good = 1;
}
if(dp[i][j] != -1 || (i == 0 && j == 0)){
dp[i + 1][j] = max(dp[i+1][j], P[dp[i][j]] + dp[i][j]);
dp[i][j + 1] = max(dp[i][j + 1], Q[dp[i][j]] + dp[i][j]);
}
//cerr << "(" << i << "," << j << ") " << dp[i][j] << endl;
}
}
if(good){
hi = mid - 1;
}
else{
lo = mid + 1;
}
}
cout << lo << endl;
}
