#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N = 40;
LL c[N][N];
int main() {
    // 预处理组合数
    for (int i = 0; i < N; i++)
        for (int j = 0; j <= i; j++)
            if (!j)
                c[i][j] = 1;
            else
                c[i][j] = c[i - 1][j - 1] + c[i - 1][j];

    int n;
    cin >> n;
    // 卡特兰数
    cout << c[n * 2][n] / (n + 1) << endl;
    return 0;
}