+ Time limit: 0.5 seconds + Memory limit: 64 megabytes ---------- Dara and Sara are siblings. During the New Year ceremony, the grandmother bought $n$ dolls for them. The sizes of these dolls range from $1$ to $n$. $1$ is the smallest and $n$ is the largest. These $n$ dolls are for both of them, and they are going to play with them together. The grandmother wants to show them the dolls in a specific order. Dara loves big gifts and Sara loves small gifts. + If Dara sees a doll larger than all the dolls that have appeared so far, he screams. + If Sara sees a doll smaller than all the dolls that have appeared so far, she screams. For example, after the first doll appears, both of them scream. [Image explanation] The grandmother wants to show the dolls in an order that minimizes the total number of screams from Dara and Sara. Tell the grandmother the minimum number of screams she will hear in the best possible order. # Input The single line of input contains the positive integer $n$, which represents the number of dolls. $$1 \leq n \leq 100$$ # Output Print the minimum total number of screams from Dara and Sara on the single line of output. # Examples ## Sample Input 1 ``` 1 ``` ## Sample Output 1 ``` 2 ``` In this case, the grandmother only has one doll, and upon showing it, both Dara and Sara scream. Thus, the total number of screams will be $2$. ---------- ## Sample Input 2 ``` 2 ``` ## Sample Output 2 ``` 3 ``` In this case, the grandmother can: + In the first step, show doll $1$. Upon seeing it, both Dara and Sara scream. + In the second step, show doll $2$. Upon seeing this doll, Dara screams once. Therefore, the total screams will be $2 + 1 = 3$. ---------- ## Sample Input 3 ``` 3 ``` ## Sample Output 3 ``` 3 ``` In this case, the grandmother can: + In the first step, show doll $1$. Upon seeing it, both Dara and Sara scream. + In the second step, show doll $3$. Upon seeing this doll, Dara screams once. + In the third step, show doll $2$. Neither of them screams upon seeing it. Therefore, the total screams will be $2 + 1 + 0 = 3$. ----------