#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 7;
long long dp[2007][1007];
int main() {
  int n;
  scanf("%d", &n);
  dp[0][0] = 1;
  long long ans = 0;
  for (int i = 1; i <= 2 * n; i++) {
    for (int j = 0; j <= n; j++) {
      dp[i][j] = ((dp[i][j] + dp[i - 1][j + 1]) % 1000000007);
      if (i + j <= 2 * n) {
        dp[i][j] = ((dp[i][j] + dp[i - 1][j - 1]) % 1000000007);
      }
      if (i & 1) ans = ((ans + dp[i][j]) % 1000000007);
    }
  }
  printf("%lld\n", ans);
  return 0;
}
