#include <bits/stdc++.h>
#define TASK "watch"
#define endl mmm
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define BIT(i,x) (((i)>>(x))&1)
#define FOR(i,a,b) for(int i = (a); i<=(b); i++)
#define FORD(i,a,b) for(int i = (a); i>=(b); i--)
#define all(C) (C).begin(), (C).end()
using namespace std;
using ll = long long;
using pii = pair<int,int>;
const int INT_LIM = 2147483647;
const ll LL_LIM = 9223372036854775807;
template <typename X> bool minimize(X &x, const X &y) {if (x>y){x = y; return true;}return false;}
template <typename X> bool maximize(X &x, const X &y) {if (x<y){x = y; return true;}return false;}
///------------------------------------------///
int n, p, q;
ll a[2048];
void inp()
{
cin >> n >> p >> q;
minimize(p, n);
minimize(q, n);
FOR(i, 1, n) cin >> a[i];
sort(a+1, a+1+n);
}
int b[2048], c[2048];
int f[2048][2048];
bool check(ll r)
{
deque<int> dq;
FORD(i, n, 1)
{
dq.pb(i);
while (a[dq.front()]>=a[i]+r) dq.pop_front();
b[i] = dq.front();
}
while (!dq.empty()) dq.pop_front();
FORD(i, n, 1)
{
dq.pb(i);
while (a[dq.front()]>=a[i]+r*2) dq.pop_front();
c[i] = dq.front();
}
FOR(i, 0, p) FOR(j, 0, q) f[i][j] = 0;
f[0][0] = 1;
FOR(i, 0, p) FOR(j, 0, q) if (f[i][j])
{
// cout << i << ' ' << j << ' ' << f[i][j] << '\n';
if (f[i][j]==n+1) return true;
if (i<p) maximize(f[i+1][j], b[f[i][j]]+1);
if (j<q) maximize(f[i][j+1], c[f[i][j]]+1);
}
return false;
}
void solve()
{
ll l = 1, r = 1e9, ret = 0;
// FOR(i, 1, 5) cout << check(i) << '\n';
while (l<=r)
{
int mid = (l+r)>>1;
if (check(mid))
{
ret = mid;
r = mid-1;
}
else l = mid+1;
}
cout << ret;
}
signed main()
{
///--------------------------///
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
if (fopen(TASK".INP","r")!=NULL)
{
freopen(TASK".INP","r",stdin);
freopen(TASK".OUT","w",stdout);
}
///--------------------------///
int NTEST = 1;
bool multitest = 0;
if (multitest) cin >> NTEST;
while (NTEST--)
{
inp();
solve();
}
return 0;
}
///------------------------------------------///
