#include<bits/stdc++.h>
#include<algorithm>
#include<random>
#include<chrono>
#include<cstdlib>
#include<ctime>
#include<numeric>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<queue>
#include<iomanip>
//#define int long long
#define ll long long
#define L LLONG_MAX
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define sz(a) ((int)a.size())
#define FOR(i,j,k) for(int i=j;i<=k;i++)
#define REP(i,k,j) for(int i=k;i>=j;i--)
#define FORD(i,a) for(auto i:a)
#define MASK(i) ((1)<<(i))
#define rngdcl mt19937_64 rng(chrono::steady_clock::now().time_asince_epoch().count())
#define random(l,r) ((l)+(rng()%(r-l+1)))
using namespace std;
const int nmax=2001;
int n,p,q;
vector<int> a;
int dp[nmax][nmax];
void input()
{
cin >> n >> p >> q;
a.push_back(0);
FOR(i,1,n)
{
int x; cin >> x;
a.push_back(x);
}
}
bool check(int w)
{
FOR(i,0,p) dp[1][i]=q;
FOR(i,2,n+1) FOR(j,0,p) dp[i][j]=INT_MIN;
FOR(i,1,n)
{
int small=upper_bound(a.begin(),a.end(),a[i]+w-1)-a.begin();
int large=upper_bound(a.begin(),a.end(),a[i]+2*w-1)-a.begin();
FOR(j,0,p)
{
dp[small][j-1]=max(dp[small][j-1],dp[i][j]);
dp[large][j]=max(dp[large][j],dp[i][j]-1);
}
}
int ans=INT_MIN;
FOR(i,0,p) ans=max(ans,dp[n+1][i]);
// if(w==4)
// {
// FOR(i,1,n+1) {FOR(j,0,p) cout << dp[i][j] << ' '; cout << '\n';}
// }
if(ans<0) return false;
else return true;
}
void solve()
{
p=min(p,n);
q=min(q,n);
int l=0,r=1e9;
while(l+1<r)
{
int mid=(l+r)/2;
if(check(mid)) r=mid;
else l=mid;
}
cout << r;
}
int main()
{
//freopen(".inp", "r", stdin);
//freopen(".out", "w", stdout);
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
input();
solve();
}
