#include <bits/stdc++.h>
int main() {
  int a[1000010] =
      {
          0,
      },
      b[1000010] = {
          0,
      };
  int n, j;
  a[0] = 1;
  a[1] = 1;
  b[1] = 1;
  scanf("%d", &n);
  for (int i = 2; i <= n; i++) {
    j = i;
    a[j] = (a[j - 1] + a[j - 2]) % 1000000007;
    b[j] = (a[j] + b[j - 1]) % 1000000007;
  }
  printf("%d", b[n]);
  return 0;
}
