#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int n, tip[2002][2002], dp[2002][2002];
int main() {
  cin >> n;
  n = 2 * n;
  tip[0][0] = 1;
  for (int i = 1; i <= n; i++)
    for (int j = 0; j <= i; j++) {
      if (j != 0) {
        dp[i][j] = (dp[i - 1][j - 1] + dp[i][j]) % mod;
        tip[i][j] |= tip[i - 1][j - 1];
      }
      if (j + 1 <= i - 1) {
        dp[i][j] = (dp[i - 1][j + 1] + dp[i][j]) % mod;
        tip[i][j] |= tip[i - 1][j + 1];
      }
      dp[i][j] += tip[i][j];
      dp[i][j] %= mod;
      tip[i][j] ^= 1;
    }
  cout << dp[n][0];
  return 0;
}
