#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
ll powmod(ll x,ll n){
    if(n == 0)return 1;
    ll ans = powmod(x*x%MOD,n/2);
    if(n % 2)ans = ans * x % MOD;
    return ans;
}
ll divmod(ll a,ll b){
    return ((a%MOD) * (powmod(b,MOD-2)%MOD)) % MOD;
}
ll combi(ll n,ll r){
    ll num = 1;
    for(ll i = 1;i <= r;i++){
        num = divmod((n-i+1)*num,i);
    }
    return num;
}
main(){
    int N;
    cin >> N;
    cout << combi(2 * N, N)  / (N+1) << endl;
}