## The Perfect Gift

It is the season of giving and

is making a gift for his idol, .likes most natural numbers (\(1, 2, 3, 4, ..\)), but not all natural numbers. Specifically, doesn't like square numbers. So, decided to write a list of all the natural numbers that likes (all natural numbers except for square numbers).

Unfortunately,

is practicing for the CCC, so he asks you to help him out a bit. wants to know what the \(Q\)-th element of his list is.#### Constraints

\(1 \le Q \le 10^9\)

##### Subtask 1 [30%]

\(1 \le Q \le 10^5\)

#### Input Specification

The first and only line contains an integer \(Q\), which is the index of the element you want to find.

#### Output Specification

Output the \(Q\)-th element of his list.

#### Sample Input

`5`

#### Sample Output

`7`

#### Explanation

's list starts with \([2, 3, 5, 6, 7]\). Therefore, the fifth element of his list is \(7\).

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