#include <bits/stdc++.h>
using namespace std;
int in[50];
int ans[4][4001];
int main() {
  int input = 0;
  while (cin >> in[input]) {
    if (in[input] == EOF) break;
    input++;
  }
  for (int k = 0; k < 4; k++) ans[k][0] = 1;
  for (int n = 0; n < 4000; n++) ans[0][n] = 1;
  for (int k = 1; k < 4; k++) {
    for (int n = 1; n < 4000; n++) {
      ans[k][n] = ans[k - 1][n] + ans[k][n - 1];
    }
  }
  for (int h = 0; h < input; h++) cout << ans[3][in[h] - 1] << endl;
  return 0;
}
