#include <bits/stdc++.h>
using namespace std;
const int N=2005;
int n,P,Q,res;
int a[N],dp_before[N],dp_cur[N];
bool check(int mid)
{
int Lp;
int lQ;
dp_before[0]=dp_cur[0]=0;
Lp=1;
for (int i=1;i<=n;i++)
{
while (a[i]-a[Lp]+1>mid) Lp++;
dp_before[i]=dp_before[Lp-1]+1;
}
if (dp_before[n]<=P) return true;
for (int j=1;j<=Q;j++)
{
Lp=1;
lQ=1;
for (int i=1;i<=n;i++)
{
while (a[i]-a[Lp]+1>mid) Lp++;
while (a[i]-a[lQ]+1>2*mid) lQ++;
dp_cur[i]=dp_before[lQ-1];
dp_cur[i]=min(dp_cur[i],dp_cur[Lp-1]+1);
}
for (int i=1;i<=n;i++)
dp_before[i]=dp_cur[i];
if (dp_cur[n]<=P) return true;
}
return false;
}
int main()
{
ios_base::sync_with_stdio(NULL);
cin.tie(NULL); cout.tie(NULL);
cin >> n >> P >> Q;
if (P+Q>=n)
{
cout << 1;
return 0;
}
for (int i=1;i<=n;i++)
cin >> a[i];
sort(a+1,a+n+1);
res=0;
int l=1;
int r=1e9;
int mid;
while (l<=r)
{
mid=(l+r)/2;
if (check(mid))
{
res=mid;
r=mid-1;
}
else l=mid+1;
}
cout << res;
}
