#include <iostream>
#include <algorithm>
using namespace std;
const int N = 2005;
int dp[N][N], a[N], NxtP[N], NxtQ[N];
int MinQ(int n, int p, int w){
for (int i=1, r = 1, R = 1;i<=n;i++){
while (r < n and a[r+1] - a[i] + 1 <= w)
r++;
while (R < n and a[R+1] - a[i] + 1 <= 2 * w)
R++;
NxtP[i] = r;
NxtQ[i] = R;
}
for (int i=0;i<=n;i++){
for (int j=0;j<=p;j++)
dp[i][j] = 1e9;
}
dp[0][0] = 0;
int Ans = 1e9;
for (int i=1;i<=n;i++){
for (int j=0;j<=p;j++){
dp[NxtQ[i]][j] = min(dp[NxtQ[i]][j], dp[i-1][j] + 1);
dp[NxtP[i]][j+1] = min(dp[NxtP[i]][j+1], dp[i-1][j]);
if (i == n and Ans > dp[i][j])
Ans = dp[i][j];
}
}
return Ans;
}
int main(){
int n, p, q;
cin>>n>>p>>q;
p = min(p, n);
q = min(q, n);
for (int i=1;i<=n;i++)
cin>>a[i];
sort(a + 1, a + n + 1);
int l = 0, r = 1e9;
while (l + 1 < r){
int mid = (l + r) / 2;
if (MinQ(n, p, mid) <= q)
r = mid;
else
l = mid;
}
cout<<r<<'\n';
}
