#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int n;
pair<int, bool> f[2003][2003];
int add(int a, int b) {
  int s = a + b;
  return (s < mod ? s : s - mod);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  n *= 2;
  f[0][0] = pair<int, bool>(0, true);
  for (int len = 1; len <= n; len++)
    for (int bal = 0; bal <= len; bal++) {
      int s = 0;
      bool get = false;
      if (bal > 0) {
        s = add(s, f[len - 1][bal - 1].first);
        get |= f[len - 1][bal - 1].second;
      }
      if (bal < len) {
        s = add(s, f[len - 1][bal + 1].first);
        get |= f[len - 1][bal + 1].second;
      }
      f[len][bal] = pair<int, bool>(add(s, get), !get);
    }
  cout << f[n][0].first;
}
