Problem:
Score : 200 points

Problem Statement

Find the largest square number not exceeding N. Here, a square number is an integer that can be represented as the square of an integer.

Constraints

1 \leq N \leq 10^9

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the largest square number not exceeding N.

Sample Input 1

10

Sample Output 1

9

10 is not square, but 9 = 3 × 3 is. Thus, we print 9.

Sample Input 2

81

Sample Output 2

81

Sample Input 3

271828182

Sample Output 3

271821169

Solution in JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict'

function main(s) {

  const n = Number(s);

  let max = 0;
  let i = 0;

  while (max < n) {
    i += 1;
    max = Math.pow(i, 2);
  }

  const ans = Math.pow(i - 1, 2);

  console.log(ans);
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));