Problem Description

You are given a positive integer $ N $. Output the largest integer $ A $ such that $ A^2 $ does not exceed $ N $.

Input Format

The input is given from the standard input in the following format:

$ N $

Output Format

Output the largest integer $ A $ such that $ A^2 $ does not exceed $ N $.

Sample Input and Output

Sample Input #1

10

Sample Output #1

3

Sample Input #2

100

Sample Output #2

10

Notes/Hints

Constraints

• $1 \leq N \leq 10^9$

见题面 Input 部分

见题面 Output 部分