#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define name "a"
using namespace std;
using ii = pair<int,int>;
using aa = array<int,3>;
const int N = 1e5+5;
int a[N];
int dp[2005][2005];
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,p,q;
cin >> n >> p >> q;
for(int i=1;i<=n;i++) {
cin >> a[i];
}
sort(a+1,a+1+n);
int l=1,r=1e9;
int ans=0;
while(l<=r) {
int mid = l + r >> 1;
dp[0][0]=0;
bool c=0;
//cout << mid << endl;
for(int j=0;j<=n;j++) {
int k=1;
int huytran=1;
for(int i=1;i<=n;i++) {
while(k<=n && a[k]<=a[i]-mid) {
k++;
}
while(huytran<=n && a[huytran]<=a[i]-mid*2) {
huytran++;
}
dp[i][j]=1e9;
if(j==0) {
dp[i][j]=dp[huytran-1][j]+1;
} else
dp[i][j]=min({dp[k-1][j-1],dp[huytran-1][j]+1});
if(i==n && dp[i][j]<=p && j<=q) {
c=1;
//cout << "anhuytran " << i << ' ' << j << ' ' << dp[i][j] << endl;
}
//cout << i << ' ' << j << ' ' << k << ' ' << dp[i][j] << endl;
}
//cout << endl;
}
//cout << endl;
if(c) {
ans=mid;
r=mid-1;
}
else {
l=mid+1;
}
}
cout << ans;
return 0;
}
