#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define BIT(mask, x) ((mask >> (x)) & 1)
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; --i)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int maxn = 2e3 + 3;
int n, nbig, nsmall, a[maxn];
bool check(const int &w)
{
vector<vector<int>> dp(n + 1, vector<int>(nbig + 1, 1e9));
dp[0][0] = 0;
int jbig = 1, jsmall = 1;
FOR(i, 1, n)
{
while (jbig < i && a[i] - a[jbig] + 1 > 2 * w) ++jbig;
while (jsmall < i && a[i] - a[jsmall] + 1 > w) ++jsmall;
FOR(big, 0, nbig)
{
if (big) dp[i][big] = min(dp[i][big], dp[jbig - 1][big - 1]);
if (dp[jsmall - 1][big] < nsmall) dp[i][big] = min(dp[i][big], dp[jsmall - 1][big] + 1);
}
}
FOR(i, 0, nbig) if (dp[n][i] <= nsmall) return true;
return false;
}
void solve()
{
cin >> n >> nsmall >> nbig;
nsmall = min(nsmall, n);
nbig = min(nbig, n);
while (nbig > 0 && nbig + nsmall > n) --nbig;
FOR(i, 1, n) cin >> a[i];
sort(a + 1, a + n + 1);
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;
}
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define TASK "TEST"
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
freopen(TASK".OUT", "w", stdout);
}
solve();
return 0;
}
/* NOTES:
*/
