#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 2e3;
int n, p, q, arr[N + 5], nex[N + 5][2], dp[N + 5][N + 5];
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> p >> q;
for (int i = 1; i <= n; i++) cin >> arr[i];
if (p + q >= n) { cout << 1 << '\n'; return 0; }
sort(arr + 1, arr + n + 1);
int l = 1, r = 1e9, ans = 1e9;
while (l <= r) {
int m = (l + r)/2;
for (int i = 1; i <= n; i++) {
for (int j = i; j <= n; j++) {
if (arr[j] - arr[i] + 1 <= m) nex[i][0] = j;
if (arr[j] - arr[i] + 1 <= 2*m) nex[i][1] = j;
}
}
for (int i = 0; i <= p; i++) {
for (int j = 0; j <= q; j++) {
dp[i][j] = 0;
}
}
for (int i = 0; i <= p; i++) {
for (int j = 0; j <= q; j++) {
dp[i + 1][j] = max(dp[i + 1][j], nex[min(n, dp[i][j] + 1)][0]);
dp[i][j + 1] = max(dp[i][j + 1], nex[min(n, dp[i][j] + 1)][1]);
}
}
if (dp[p][q] == n) ans = m, r = m - 1;
else l = m +1;
}
cout << ans << '\n';
return 0;
}
