#include <bits/stdc++.h>
#define ll long long
#define go ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
using namespace std;

int const N = 1e3 + 2;
int const mod = 1e9 + 7;
int const acceptable_mask = 28; // in binary : 11100
int const clear_mask = 31;      // in binary : 11111
int n;
ll dp[N][N][1 << 5][2];
ll dpf(int i, int open, int mask, bool ok)
{

    if (i == n)
    {
        if (mask == acceptable_mask  ok)
        {
            return (open == 0 ? 1 : 0);
        }
        return 0;
    }
    ll &ret = dp[i][open][mask][ok];
    if (ret + 1)
    {
        return ret;
    }
    ret = 0;
    mask <<= 1;
    mask &= clear_mask;
    // close
    if (open - 1 >= 0)
    {
        ret += dpf(i + 1, open - 1, mask, ok  (mask == acceptable_mask));
    }
    // open
    mask |= 1;
    ret += dpf(i + 1, open + 1, mask, ok || (mask == acceptable_mask));
    return ret;
}
void solve()
{
    cin >> n;
    memset(dp, -1, sizeof(dp));
    cout << dpf(0, 0, 0, false);
}

int main()
{
    int t = 1;
    // cin>>t;
    // go;
    while (t--)
    {
        solve();
        cout << "\n";
    }
    return 0;
}