import java.io.InputStream;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;

public class Main {
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        Solver solver = new Solver(System.in, out);
        solver.solve();
        out.close();
    }
}
class Solver {
	Scanner sc;
	PrintWriter out;
    public Solver(InputStream in, PrintWriter out) {
    	sc = new Scanner(in);
    	this.out = out;
    }
    // ==================================================================
    public void solve() {
    	int N = Integer.parseInt(sc.next());
    	int l , r;
    	long ans = 0;
    	boolean f;
    	for (int i = 0; i < (1 << N * 2); i++) {
			if(Integer.bitCount(i) != N)	continue;
			l = r = 0;
			f = true;
			for (int j = (2 * N - 1); j >= 0; j--) {
				if(((i >> j) & 1) == 1) {
					l++;
				} else {
					r++;
					if(r > l) {
						f = false;
						break;
					}
				}
			}
			if(f)	ans++;
		}
    	out.println(ans);
    }    
    // ==================================================================
}