#include <bits/stdc++.h>
using namespace std;
const int maxn = 1005;
const int base = 1e9 + 7;
int n, ans;
int f[2][maxn];
int main() {
  scanf("%d", &n);
  f[0][0] = 1;
  for (int i = 1; i <= n * 2; i++) {
    int b = i & 1;
    int a = 1 - b;
    int tmp = 0;
    for (int j = 0; j <= i && j <= n; j++) {
      f[b][j] = (f[a][j + 1] + (j > 0 ? f[a][j - 1] : 0)) % base;
      if (n * 2 - i >= j) tmp = (tmp + f[b][j]) % base;
    }
    if (i & 1) ans = (ans + tmp) % base;
  }
  printf("%d\n", ans);
  return 0;
}
