#include <bits/stdc++.h>
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define FOD(i, a, b) for(int i = (a); i >= (b); i--)
#define file(name) if(fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define el cout << '\n'
#define maxn int(2e3 + 5)
using namespace std;
int n, P, Q, a[maxn];
namespace subtask1 {
bool check() {
return n <= 100;
}
bool dp[105][105][105];
bool valid(int w) {
memset(dp, 0, sizeof dp);
int small = 0, big = 0;
dp[0][0][0] = 1;
FOR(i, 1, n) {
while(small + 1 <= i && a[i] - a[small + 1] > w - 1) small++;
while(big + 1 <= i && a[i] - a[big + 1] > 2 * w - 1) big++;
FOR(j, 0, min(i, P))
FOR(k, 0, min(i, Q)) {
if(j >= 1) {
dp[i][j][k] |= dp[i - 1][j - 1][k];
dp[i][j][k] |= dp[small][j - 1][k];
}
if(k >= 1) {
dp[i][j][k] |= dp[i - 1][j][k - 1];
dp[i][j][k] |= dp[big][j][k - 1];
}
}
}
return dp[n][P][Q];
}
void solve() {
int l = 1, r = 1e9, res = 0;
while(l <= r) {
int mid = (l + r) >> 1;
if(valid(mid)) res = mid, r = mid - 1;
else l = mid + 1;
}
cout << res;
}
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> P >> Q;
FOR(i, 1, n) cin >> a[i];
sort(a + 1, a + n + 1);
if(P + Q >= n) return cout << 1, 0;
if(subtask1::check()) return subtask1::solve(), 0;
return 0;
}
