/*
_ __ __ __ ____ ___ _ __
| | /| / / ___ _ / /_ ____ / / / __ \ ___ ___ / _ \ (_) ___ ____ ___ / /
| |/ |/ / / _ `// __// __/ / _ \ / /_/ / / _ \/ -_) / ___/ / / / -_)/ __// -_) /_/
|__/|__/ \_,_/ \__/ \__/ /_//_/ \____/ /_//_/\__/ /_/ /_/ \__/ \__/ \__/ (_)
*/
#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
// #pragma GCC target("avx2")
#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define ld long double
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define rsz resize
#define fi first
#define se second
#define LMAX LLONG_MAX
#define LMIN LLONG_MIN
#define IMAX INT_MAX
#define IMIN INT_MIN
#define endl "\n"
#define newline cout << endl;
using namespace std;
// constants
// functions
// structs
// globals
// notes
/*
My favorite anime is One Piece(obviously)
My oshi(Yes, I have an oshi, deal with it) is Kamil_Tsubaki
-stuff you should look for-
* int overflow, array bounds
* special cases (n=1?)
* do something instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
continue - skip the rest in the loop
*/
void solve()
{
int n, S, B;
cin >> n >> S >> B;
vector <int> es(n + 1, 0);
for (int i = 1; i <= n; i++)
{
cin >> es[i];
}
sort(all(es));
S = min(n, S);
B = min(n, B);
auto check = [&](int x)
{
vector <int> nxt(n + 2), nxt2(n + 2);
nxt[n + 1] = nxt2[n + 1] = n + 1;
for (int i = 1; i <= n; i++)
{
nxt[i] = lower_bound(all(es), es[i] + x) - es.begin();
nxt2[i] = lower_bound(all(es), es[i] + 2 * x) - es.begin();
}
vector <vector <int> > dp(S + 1, vector <int>(B + 1, 1));
for (int i = 0; i <= S; i++)
{
for (int j = 0; j <= B; j++)
{
if (dp[i][j] > n)
{
return true;
}
if (i < S)
{
dp[i + 1][j] = max(dp[i + 1][j], nxt[dp[i][j]]);
}
if (j < B)
{
dp[i][j + 1] = max(dp[i][j + 1], nxt2[dp[i][j]]);
}
}
}
return dp[S][B] > n;
};
int L = 1, R = 1e9;
while (L <= R)
{
int mid = L + R >> 1;
if (check(mid))
{
R = mid - 1;
}
else
{
L = mid + 1;
}
}
cout << L;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while (t--)
{
solve();
newline
}
}
/*
$$$$$$$$\ $$$$$$$$\
$$ _____|\____$$ |
$$ | $$ /
$$$$$\ $$ /
$$ __| $$ /
$$ | $$ /
$$$$$$$$\ $$$$$$$$\
\________|\________|
*/
