#include <bits/stdc++.h>
using namespace std;
#define int long long
const int MOD = 1e9 + 7;
void solve(int tc) {
int N, P, Q;
cin >> N >> P >> Q;
P = min(P, N);
Q = min(Q, N);
int A[N+1];
for(int i=1; i<=N; i++) cin >> A[i];
sort(A+1, A+N+1);
int lb = 1, rb = 1e9;
while(lb < rb) {
int w = (lb+rb) >> 1;
int dp[P+1][Q+1]; // max index we can reach by P small and Q big
dp[0][0] = 0;
int sing[N+1], doub[N+1];
for(int i=1; i<=N; i++) {
for(int j=i; j<=N; j++) {
if(A[j] - A[i] + 1 <= w) sing[i] = j;
if(A[j] - A[i] + 1 <= 2*w) doub[i] = j;
}
}
int idx = 0;
for(int i=1; i<=P; i++) {
dp[i][0] = (idx == N ? N : sing[idx + 1]);
idx = dp[i][0];
}
idx = 0;
for(int i=1; i<=Q; i++) {
dp[0][i] = (idx == N ? N : doub[idx + 1]);
idx = dp[0][i];
}
for(int i=1; i<=P; i++) {
for(int j=1; j<=Q; j++) {
dp[i][j] = max(
(dp[i-1][j] == N ? N : sing[dp[i-1][j] + 1]),
(dp[i][j-1] == N ? N : doub[dp[i][j-1] + 1])
);
}
}
if(dp[P][Q] == N) rb = w;
else lb = w+1;
}
cout << lb << "\n";
}
signed main() {
int t = 1;
//cin >> t;
for(int i=1; i<=t; i++) {
solve(i);
}
}
