#include <bits/stdc++.h>
using namespace std;
long long n, f[3010][3010];
long long ans;
int main() {
  scanf("%lld", &n);
  f[1][1] = 1;
  for (int i = 2; i <= n + 1; i++) {
    for (int j = 1; j <= i; j++) {
      f[i][j] = (f[i - 1][j] + f[i][j - 1]) % 1000000007;
      if ((i + j) % 2) {
        ans = (ans + f[i][j]) % 1000000007;
      }
    }
  }
  printf("%lld", ans);
}
