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