#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
constexpr ll mod = 1000000007;
ll dp[2007][2007];
ll num[2007];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  n *= 2;
  dp[0][0] = 1;
  for (int i = 1; i <= n; i++) {
    for (int j = 0; j <= n - i; ++j) {
      if (j > 0) dp[i][j] += dp[i - 1][j - 1];
      dp[i][j] %= mod;
      if (j < i) dp[i][j] += dp[i - 1][j + 1];
      dp[i][j] %= mod;
      num[i] += dp[i][j];
      num[i] %= mod;
    }
  }
  ll res = 0;
  ll resA = 0;
  for (int i = 1; i < n; i += 2) {
    resA += num[i];
    resA %= mod;
  }
  cout << max(res, resA) << endl;
}
