#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#pragma target("avx2")
#define int long long
using namespace std;
int n, p, q;
int positions[2005];
int nextw[2005];
int next2w[2005];
bool seen[2005][2005];
int cached[2005][2005];
int dp(int big, int small) {
if(seen[big][small]) return cached[big][small];
int maxdist = -1;
seen[big][small] = true;
if(small != 0) {
if(dp(big, small-1) == n-1) return cached[big][small] = n-1;
maxdist = max(maxdist, nextw[dp(big, small-1) + 1]);
}
if(big != 0) {
if(dp(big-1, small) == n-1) return cached[big][small] = n-1;
maxdist = max(maxdist, next2w[dp(big - 1, small) + 1]);
}
return cached[big][small] = maxdist;
}
bool check(int val) {
memset(seen, false, sizeof(seen));
int r = 1;
for(int i = 0; i < n; i++) {
while(r != n && positions[r] < positions[i] + val) {
r++;
}
nextw[i] = r - 1;
}
r = 1;
for(int i = 0; i < n; i++) {
while(r != n && positions[r] < positions[i] + 2 * val) {
r++;
}
next2w[i] = r - 1;
}
if(dp(q, p) == n-1) {
return true;
}
return false;
}
signed main() {
cin >> n >> p >> q;
p = min(p, n);
q = min(q, n);
for(int i = 0; i < n; i++) cin >> positions[i];
sort(positions, positions + n);
int l = 1, r = 1e9 + 5;
while(r > l + 1) {
int mid = (l + r) / 2 - 1;
if(check(mid)) {
r = mid + 1;
}else {
l = mid + 1;
}
}
cout<<l<<'\n';
}
