#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize("-Ofast")
#include <bits/stdc++.h>
#include <algorithm>
#include <iostream>
#include <vector>
#include <limits>
#include <cmath>
#include <stack>
#include <queue>
#include <map>
#include <math.h>
using namespace std;
using ll = long long;
ll INF = 2 * 1E9;
void solve(){
ll n, p, q;
cin >> n >> p >> q;
vector<ll> list_n(n, 0);
for(ll i = 0; i < n; i++){
cin >> list_n[i];
}
if(p + q >= n){
cout << 1 << endl;
return;
}
ll l = 1;
ll r = 15;
while(l + 1 < r){
ll mid = (l + r)/2;
vector<vector<ll>> dp(n + 1, vector<ll>(p + 1, INF));
dp[0][0] = 0;
for(ll i = 0; i < n; i++){
for (int j = 0; j <= p; j++) {
if(dp[i][j] == INF){
continue;
}
if(j != p){
ll left = i;
ll right = n;
while(left + 1 < right){
ll middle = (left + right)/2;
if(list_n[middle] < list_n[i] + mid){
left = middle;
}else{
right = middle;
}
}
dp[left + 1][j + 1] = min(dp[i][j], dp[left + 1][j + 1]);
}
// Increase the bigger thingy
ll left = i;
ll right = n;
while(left + 1 < right){
ll middle = (left + right)/2;
if(list_n[middle] < list_n[i] + 2*mid){
left = middle;
}else{
right = middle;
}
}
dp[left + 1][j] = min(dp[i][j] + 1, dp[left + 1][j]);
}
}
bool pos = false;
for(ll i = 0; i <= p; i++){
if(dp[n][i] <= q){
pos = true;
break;
}
}
//cout << mid << " " << pos << endl;
if(pos){
r = mid;
}else{
l = mid;
}
}
cout << r;
}
bool single = true;
signed main(){
ios_base::sync_with_stdio(false);
cout.tie(0);
cin.tie(0);
ll t = 1;
if(!single) cin >> t;
while(t--){
solve();
}
}
