#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int MAX = 2001;
long long dp[MAX][MAX];
const int M = MAX / 2;
void solve() {
  int a, b;
  cin >> a;
  a *= 2;
  long long ans = 1;
  dp[1][1] = 1;
  for (int i = 2; i <= a; ++i) {
    int MX = a / 2;
    int brd = a / 2;
    if (i > a / 2) {
      MX = MX - (i - MX - 1);
      brd = MX - 1;
    }
    for (int j = 0; j <= brd; ++j) {
      if (j - 1 >= 0) {
        dp[i][j] = (dp[i][j] + dp[i - 1][j - 1]) % MOD;
        if (i % 2 != 0) {
          ans = (ans + dp[i - 1][j - 1]) % MOD;
        }
      }
      if (j + 1 <= MX) {
        dp[i][j] = (dp[i][j] + dp[i - 1][j + 1]) % MOD;
        if (i % 2 != 0) {
          ans = (ans + dp[i - 1][j + 1]) % MOD;
        }
      }
    }
  }
  cout << ans << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  int test = 1;
  while (test-- > 0) {
    solve();
  }
  return 0;
}
