[코딩테스트] You're a square!

You're a square!A square of squaresYou like building blocks.

You especially like building blocks that are squares.And what you even like more, is to arrange them into a square of square building blocks!However, sometimes, you can't arrange them into a square.

Instead, you end up with an ordinary rectangle!Those blasted things!

If you just had a way to know, whether you're currently working in vain…Wait! That's it!

You just have to check if your number of building blocks is a perfect square.Task:Given an integral number, determine if it's a square number:In mathemati..........