题目描述
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-----
10
-----Sample Output-----
9
10 is not square, but 9 = 3 × 3 is. Thus, we print 9.
输入格式
见题面
输出格式
见题面
样例输入
10
样例输出
9