/**************************************************************

    Problem:hdu 1028

    User: youmi

    Language: C++

    Result: Accepted

    Time:15MS

    Memory:1908K

****************************************************************/

//#pragma comment(linker, "/STACK:1024000000,1024000000")

//#include<bits/stdc++.h>

#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <map>

#include <stack>

#include <set>

#include <sstream>

#include <cmath>

#include <queue>

#include <deque>

#include <string>

#include <vector>

#define zeros(a) memset(a,0,sizeof(a))

#define ones(a) memset(a,-1,sizeof(a))

#define sc(a) scanf("%d",&a)

#define sc2(a,b) scanf("%d%d",&a,&b)

#define sc3(a,b,c) scanf("%d%d%d",&a,&b,&c)

#define scs(a) scanf("%s",a)

#define sclld(a) scanf("%I64d",&a)

#define pt(a) printf("%d\n",a)

#define ptlld(a) printf("%I64d\n",a)

#define rep(i,from,to) for(int i=from;i<=to;i++)

#define irep(i,to,from) for(int i=to;i>=from;i--)

#define Max(a,b) ((a)>(b)?(a):(b))

#define Min(a,b) ((a)<(b)?(a):(b))

#define lson (step<<1)

#define rson (lson+1)

#define eps 1e-6

#define oo 0x3fffffff

#define TEST cout<<"*************************"<<endl

const double pi=*atan(1.0);

using namespace std;

typedef long long ll;

template <class T> inline void read(T &n)

{

    char c; int flag = ;

    for (c = getchar(); !(c >= '' && c <= '' || c == '-'); c = getchar()); if (c == '-') flag = -, n = ; else n = c - '';

    for (c = getchar(); c >= '' && c <= ''; c = getchar()) n = n *  + c - ''; n *= flag;

}

int Pow(int base, ll n, int mo)

{

    if (n == ) return ;

    if (n == ) return base % mo;

    int tmp = Pow(base, n >> , mo);

    tmp = (ll)tmp * tmp % mo;

    if (n & ) tmp = (ll)tmp * base % mo;

    return tmp;

}

//***************************

int n;

const int maxn=+;

ll dp[maxn][maxn];

void init()

{

    zeros(dp);

    dp[][]=;

    rep(i,,)

    {

        rep(j,,i)

        {

            dp[i][j]=dp[i][j-]+dp[i-j][i-j];

            if(j<(i+)/)

                dp[i][j]-=dp[i-j][i-j]-dp[i-j][j];

        }

    }

}

int main()

{

    #ifndef ONLINE_JUDGE

    freopen("in.txt","r",stdin);

    #endif

    init();

    while(~sc(n))

    {

        ptlld(dp[n][n]);

    }

}