LogiQuest

489. Bulb Switcher

MediumMath

n bulbs start off. In round i you toggle every i-th bulb, for i = 1..n. Print how many bulbs are on at the end.

Input format

One integer n

Output format

The number of bulbs on.

Example 1

Input

3

Output

1

Example 2

Input

0

Output

0

Constraints

0 ≤ n ≤ 10⁹

Read input from standard input and print the answer to standard output. Your code is judged against 5 test cases, most of them hidden.

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