#P1974. 基因聚合

基因聚合

Description

You are given nn cards, each with the number 11, and a machine.

You will perform the following operation n1n-1 times: put two cards into the machine and obtain a new card with the number xy+1xy+1, where x,yx, y are the numbers on the two cards you put in.

Question: After performing n1n-1 operations, what is the maximum possible number on the remaining card?

Input Format

One line containing a single positive integer nn (1n1041 \le n \le 10^4).

Output Format

One line containing a single positive integer representing the answer.

3
3

Hint

Translated by ChatGPT 5