#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
using namespace std;

int main()
{
    int n;
    cin >> n;

    vector<vector<int> > dp(n+1, vector<int>(n+1, 0));
    dp[0][0] = 1;
    for(int i=0; i<=n; ++i){
        for(int j=0; j<=i; ++j){
            if(i < n)
                dp[i+1][j] += dp[i][j];
            if(j < i)
                dp[i][j+1] += dp[i][j];
        }
    }
    cout << dp[n][n] << endl;

    return 0;
}