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>
int main()
{
    int n;
    scanf("%d",&n);
    int ans;
    int k,i;
    for(i=1;i<=n;i++)
    {
        ans=0;
        ans=i*i;
        if(ans==n)
        {
            printf("%d",n);
             break;
        }
        if(ans>n)
        {
            k=i-1;
            printf("%d",k*k);
            break;
        }
    }



       return 0;
}