#include <bits/stdc++.h>
using namespace std;
template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl
using ll = long long;
const int maxn = 1e6 + 5;
int n, small, large;
int a[maxn];
map<vector<int>, bool> dp;
bool solve(int w, int i, int j, int k) {
if (j>small) return false;
if (k>large) return false;
if (i==n) return true;
vector<int> key = {i,j,k};
if (dp.count(key)) return dp[key];
bool &res = dp[key] = false;
// use small
{
int to = lower_bound(a,a+n,a[i]+w)-a;
res |= solve(w, to, j+1, k);
}
// use large
{
int to = lower_bound(a,a+n,a[i]+2*w)-a;
res |= solve(w, to, j, k+1);
}
return res;
}
bool test(int w) {
dp.clear();
return solve(w, 0, 0, 0);
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin>>n>>small>>large;
assert(n<=100);
if (small>=n || large>=n) out(1);
for (int i=0; i<n; i++) {
cin>>a[i];
}
sort(a,a+n);
int lo=0;
int hi=(int)1e9 + 20;
while (hi-lo>1) {
int mid=(lo+hi)/2;
if (test(mid)) {
hi = mid;
} else {
lo = mid;
}
}
cout<<hi<<endl;
return 0;
}
