#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
int n, p, q;
cin >> n >> p >> q;
vector<int> a(n+1);
for (int i = 1; i <= n; i++) cin >> a[i];
if (p+q >= n) {
cout << 1 << '\n';
return 0;
}
sort(a.begin(), a.end());
ll lo = 1, hi = 1e9;
while (lo < hi) {
ll mid = (lo+hi)/2;
// check if w = mid is a valid answer
vector<int> idx1(n+1), idx2(n+1);
int j = 0;
for (int i = 0; i <= n; i++) {
// if a small camera is placed at a[i+1], what is the maximum index it can reach?
while (j+1 <= n && a[j+1]-a[i+1]+1 <= mid) j++;
idx1[i] = j;
}
idx1[n] = n;
j = 0;
for (int i = 0; i <= n; i++) {
// same but for a large camera
while (j+1 <= n && a[j+1]-a[i+1]+1 <= 2*mid) j++;
idx2[i] = j;
}
idx2[n] = n;
vector<vector<int>> dp(p+1, vector<int>(q+1));
// dp[i][j] stores the maximum possible index reachable using i small cameras and j large cameras
for (int i = 0; i <= p; i++) {
for (int j = 0; j <= q; j++) {
if (i+1 <= p) dp[i+1][j] = max(dp[i+1][j], idx1[dp[i][j]]);
if (j+1 <= q) dp[i][j+1] = max(dp[i][j+1], idx2[dp[i][j]]);
}
}
bool poss = false;
for (int i = 0; i <= p; i++) {
for (int j = 0; j <= q; j++) {
if (dp[i][j] >= n) {
poss = true;
break;
}
}
if (poss) break;
}
if (poss) hi = mid;
else lo = mid+1;
}
cout << hi << '\n';
return 0;
}
