#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 7;
const int MOD = 1e9 + 7;
const int MAXN = 1e6 + 3;
long long gcd(long long a, long long b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
long long power(long long x, long long y) {
  long long res = 1;
  while (y > 0) {
    if (y & 1) res = res * x;
    y = y >> 1;
    x = x * x;
  }
  return res;
}
long long n;
const int maxn = 1e3 + 3;
long long dp1[2 * maxn][2 * maxn];
long long dp2[2 * maxn][2 * maxn];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n;
  n *= 2;
  dp1[0][0] = 0ll;
  dp2[0][0] = 1ll;
  for (long long i = 1; i <= n; i++) {
    for (long long j = 0; j <= i; j++) {
      if (j == 0) {
        dp2[i][j] = (1 + dp1[i - 1][j + 1]) % MOD;
        dp1[i][j] = max(dp1[i - 1][j + 1], dp2[i - 1][j + 1]);
      } else if (j == i) {
        dp2[i][j] = (1 + dp1[i - 1][j - 1]) % MOD;
        dp1[i][j] = max(dp1[i - 1][j - 1], dp2[i - 1][j - 1]);
      } else {
        dp2[i][j] = (1 + dp1[i - 1][j - 1] + dp1[i - 1][j + 1]) % MOD;
        dp1[i][j] = max(dp1[i - 1][j - 1] + dp2[i - 1][j + 1],
                        dp1[i - 1][j + 1] + dp2[i - 1][j - 1]) %
                    MOD;
      }
    }
  }
  cout << dp1[n][0] << '\n';
  return 0;
}
