#include <bits/stdc++.h>
using namespace std;
const double pi = 2 * acos(0.0);
const int maxn = 1e3 + 10;
const int mod = 1e9 + 7;
int dp[maxn * 2][maxn];
long long cnt[maxn * 2];
int main() {
  int n;
  cin >> n;
  dp[0][0] = 1;
  for (int i = 1; i <= 2 * n; i++) {
    for (int j = 0; j <= n; j++) {
      dp[i][j] = (dp[i - 1][j + 1] + (j > 0 ? dp[i - 1][j - 1] : 0)) % mod;
      if (i + j <= 2 * n) cnt[i] = (cnt[i] + dp[i][j]) % mod;
    }
  }
  long long ans = 0;
  for (int i = 1; i <= 2 * n; i += 2) ans = (ans + cnt[i]) % mod;
  printf("%lld\n", ans);
  return 0;
}
