#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
#define all(x) x.begin(), x.end()
const int inf = 2e9 + 5;
void solve() {
int n, p, q;
cin >> n >> p >> q;
vector<int> a(n);
for (int i = 0; i < n;i++)
cin >> a[i];
if (p + q >= n)
return (void)(cout << 1);
// a.insert(a.begin(), 0);
a.push_back(0);
sort(a.begin(), a.end());
vector dp(n + 1, vector(p + 1, vector(q + 1, inf)));
dp[0][0][0] = 0;
for (int i = 1; i <= n;i++) {
for (int j = 0; j <= p;j++) {
for (int k = 0; k <= q;k++) {
for (int f = 0; f < i;f++) {
if (j > 0)
dp[i][j][k] = min(dp[i][j][k], max(dp[f][j - 1][k], 2 * (a[i] - a[f + 1] + 1)));
if (k > 0)
dp[i][j][k] = min(dp[i][j][k], max(dp[f][j][k - 1], a[i] - a[f + 1] + 1));
}
}
}
}
int ans = inf;
for (int i = 0; i <= p;i++) {
for (int j = 0; j <= q;j++)
ans = min(ans, dp[n][i][j]);
}
// cout << ans << " ";
cout << (ans + 1) / 2;
}
signed main() {
ios :: sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
// cin >> t;
while (t--) {
solve();
cout << "\n";
}
return 0;
}
