#include <bits/stdc++.h>

using namespace std;
typedef long long LL;
const int N = 20;
int f[N];
int main() {
    int n;
    cin >> n;
    f[0] = 1;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= i; j++)
            f[i] += f[j - 1] * f[i - j];
    cout << f[n] << endl;
    return 0;
}