#include <bits/stdc++.h>
using namespace std;
int n;
const int maxN = (2e3) + 5;
const int mod = (1e9) + 7;
pair<int, int> dp[maxN][maxN];
int main() {
  scanf("%d", &n);
  n <<= 1;
  dp[0][0] = {0, 1};
  for (int len = 1; len <= n; len++) {
    for (int dif = 0; dif <= n; dif++) {
      int sum = 0;
      bool ok = 0;
      if (dif) {
        sum = (sum + dp[len - 1][dif - 1].first) % mod;
        ok |= dp[len - 1][dif - 1].second;
      }
      if ((dif + 1) <= (len - 1)) {
        sum = (sum + dp[len - 1][dif + 1].first) % mod;
        ok |= dp[len - 1][dif + 1].second;
      }
      if (ok) {
        sum = (sum + 1) % mod;
        dp[len][dif] = {sum, 0};
      } else
        dp[len][dif] = {sum, 1};
    }
  }
  cout << dp[n][0].first << '\n';
  return 0;
}
