#include <bits/stdc++.h>   using namespace std;   int arr[11][11];   int main() {     int n;     cin >> n;     for (int i = 1; i <= n; i++) {       arr[1][i] = 1;     }     for (int i = 2; i <= n; i++) {       for (int j = 1; j <= n; j++) {         arr[i][j] = arr[i - 1][j] + arr[i][j - 1];       }     }     cout << arr[n][n] << endl;     return 0;   }   