#include <cstdio>
using namespace std;

int m[100][100];

int main(void){
    freopen("dirichlet.out","w",stdout);
    freopen("dirichlet.in","r",stdin);
    int n,s;
    scanf("%d",&n);
    m[0][0]=1;
    for(int i=1; i<=n; ++i){
        s=0;
        for(int j=0; j<=i; ++j){
            s+=m[i-1][j];
            m[i][j]=s;
        }
    }
    printf("%d",m[n][n]);
    return 0;
}