#include <bits/stdc++.h>
using namespace std;
int n, f[2000 + 5][2000 + 5], ans1, ans2;
int main() {
  scanf("%d", &n);
  n *= 2;
  f[0][0] = 1;
  for (int i = 1; i <= n; ++i) {
    for (int j = 0; j <= n; ++j) {
      if (j >= 1) f[i][j] = (f[i][j] + f[i - 1][j - 1]) % 1000000007;
      f[i][j] = (f[i][j] + f[i - 1][j + 1]) % 1000000007;
    }
  }
  for (int i = 1; i <= n; i += 2)
    for (int j = 0; j <= i; ++j)
      if (n - i >= j) ans1 = (ans1 + f[i][j]) % 1000000007;
  printf("%d\n", ans1);
  return 0;
}
