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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

#include<string.h>
int main (void){
  
 long long int c,max=0,n=0,i,k,flag=0,sum=0,count;
scanf("%lld",&n);
while((i*i)<n)
{
    i++;
    
}
 printf("%ld",(i*i>n)?(i-1)*(i-1):i*i);
return 0;
    
}