#include<bits/stdc++.h>
using namespace std;

int main(){
    long long nCr[31][31];
    for(int i=0;i<31;i++)
        for(int j=0;j<31;j++)
            nCr[i][j] = 0;
    for(int i=0;i<30;i++){
        nCr[i][0] = 1;
        nCr[i][i] = 1;
    }
    for(int i=0;i<30;i++)
        for(int j=0;j<=i;j++)
            nCr[i+1][j+1] = nCr[i][j] + nCr[i][j+1];
    long long N;
    cin >> N;
    cout << (nCr[2*N][N]/(N+1)) << endl;
    return 0;
}