#include <bits/stdc++.h>
using namespace std;
int n;
vector <int> events;
vector <vector <vector <bool>>> dp;
vector <vector <vector <int>>> ready;
bool solve(int i, int p, int q, int w) {
if (i >= n)
return true;
if (ready[i][p][q] == w)
return dp[i][p][q];
bool ans = false;
if (p >= 1) {
int it = upper_bound(events.begin(), events.end(), events[i] + w - 1) - events.begin();
ans |= solve(it, p-1, q, w);
}
if (q >= 1) {
int it = upper_bound(events.begin(), events.end(), events[i] + 2*w - 1) - events.begin();
ans |= solve(it, p, q-1, w);
}
ready[i][p][q] = w;
dp[i][p][q] = ans;
return ans;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int p, q;
cin >> n >> p >> q;
events = vector <int> (n);
for (int i = 0; i < n; i++)
cin >> events[i];
sort(events.begin(), events.end());
if (p + q >= n) {
cout << 1 << '\n';
return 0;
}
dp = vector <vector <vector <bool>>> (n, vector <vector <bool>> (p+1, vector <bool> (q+1)));
ready = vector <vector <vector <int>>> (n, vector <vector <int>> (p+1, vector <int> (q+1)));
int lo = 1, hi = 1e9;
while (lo < hi) {
int mid = lo + (hi - lo) / 2;
if (solve(0, p, q, mid))
hi = mid;
else
lo = mid + 1;
}
cout << lo << '\n';
}
