#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep3(i, l, n) for (int i = l; i < n; ++i)
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define out(a) cout << a << endl
#define SZ(v) (int)v.size()
#define inf (int)(1e9+7)
int main() {
    int n; cin >> n;
    int sum = 0;
    rep(i, (1 << (2 * n))) {
        int cnt = 0;
        rep(j, 2 * n) {
            if (i & (1 << j)) { // ')'
                if (cnt <= 0) break;
                cnt--;
            } else {
                cnt++;
            }
            if (j == 2 * n - 1 && cnt == 0) {
                //out(bitset<8>(i));
                sum++;
            }
        }
    }
    out(sum);
}