#include<bits/stdc++.h>
using namespace std;
#define int long long
#define in pair<int, int>
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define INF (int)1e6
#define fast() ios_base::sync_with_stdio(false); cin.tie(NULL)
const int MX = 2e3+2;
int dp[MX][3*MX];
signed main()
{
fast();
int n, p, q;
cin >> n >> p >> q;
vector<int> a(n+1);
for(int i = 1; i <= n; i++)
cin >> a[i];
sort(a.begin()+1, a.end());
a[0] = -INF;
if(p >= n)
{
cout << "1\n";
return 0;
}
if(q >= n)
{
cout << "1\n";
return 0;
}
int ck = 0;
for(int up = (1ll<<33); up >>= 1;)
{
int w = ck+up;
//dp[i][j] stores INF, if it is not possible to cover [1, i] using at most j width stones.
//dp[i][j] = stores maximum number of 2w width getaways possible with scamming.
for(int i = 1; i <= n; i++)
dp[i][0] = -INF;
for(int i = 0; i <= (p+2*q); i++)
dp[0][i] = (i/2);
int lp1, lp2; lp1 = lp2 = 0;
for(int i = 1; i <= n; i++)
{
while(((lp1+1) <= n) && (a[lp1+1] <= (a[i]-w)))
lp1++;
while(((lp2+1) <= n) && (a[lp2+1] <= (a[i]-(2*w))))
lp2++;
dp[i][1] = dp[lp1][0];
for(int j = 2; j <= p+2*q; j++)
dp[i][j] = max(dp[lp1][j-1], 1+dp[lp2][j-2]);
}
if(dp[n][p+2*q] < q)
ck = w;
}
ck++;
cout << ck << "\n";
return 0;
}
