#include <bits/stdc++.h>
using namespace std;
const int N = 2010, mod = 1e9 + 7;
int n;
int f[N][N], g[N][N];
inline int add(const int &x, const int &y) {
  return x + y < mod ? x + y : x + y - mod;
}
inline int mul(const int &x, const int &y) {
  return (int)((long long)x * y % mod);
}
int main() {
  scanf("%d", &n), g[0][0] = 1;
  for (int i = 1; i <= n + n; i++)
    for (int j = 0; j <= n + n; j++) {
      int sum = 0, flag = 0;
      if (j) sum = add(sum, f[i - 1][j - 1]), flag |= g[i - 1][j - 1];
      if (j + 1 <= i - 1)
        sum = add(sum, f[i - 1][j + 1]), flag |= g[i - 1][j + 1];
      if (flag)
        f[i][j] = add(sum, 1), g[i][j] = 0;
      else
        f[i][j] = sum, g[i][j] = 1;
    }
  printf("%d\n", f[n + n][0]);
  return 0;
}
