Identify the time complexity of the following code as constant, linear, quadratic, cubic, log(n), nlog(n) or NP-hard. import java.io.*;
import java.security.SecureRandom;
import java.util.*;
import java.math.*;
import java.awt.geom.*;

import static java.lang.Math.*;

public class Solution implements Runnable {
    
    
    
    
    public void solve() throws Exception {
        
        int n = sc.nextInt();
        int a = sc.nextInt();
        int b = sc.nextInt();
        long h[] = new long[n];
        
        for (int i = 0;i < n; ++ i) {
            h[i] = sc.nextLong();
        }
        Arrays.sort(h);
        long l = h[n - a];
        long r = h[n - a - 1];
        out.println(l - r);
    }
    
    
    
    
    /*--------------------------------------------------------------*/
    
    static String filename = "";
    static boolean fromFile = false;
    
    BufferedReader in;
    PrintWriter out;
    FastScanner sc;
    
    public static void main(String[] args) {
        new Thread(null, new Solution(), "", 1 << 25).start();
    }
   
    public void run() {
        try {
            init();
            solve();
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            out.close();
        }
    }
    
    void init() throws Exception {
        if (fromFile) {
            in = new BufferedReader(new FileReader(filename+".in"));
            out = new PrintWriter(new FileWriter(filename+".out"));
        } else {
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        }
        sc = new FastScanner(in);
    }
}

class FastScanner {
    
    BufferedReader reader;
    StringTokenizer strTok;
    
    public FastScanner(BufferedReader reader) {
        this.reader = reader;
    }
    
    public String nextToken() throws IOException {
        while (strTok == null || !strTok.hasMoreTokens()) {
            strTok = new StringTokenizer(reader.readLine());
        }
        
        return strTok.nextToken();
    }
    
    public int nextInt() throws IOException {
        return... Complexity: