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 Python (3.4.3) (judge verdict: Runtime Error)

n=int(input())
a=0
l=[]
for a in range(1,n+1):
            for i in range(1,n):
                        if a==i**2:
                                    #print(a,i)
                                    l.append(a)
                               
print(max(l))