import java.util.Scanner;
public class Solution {
// 1. 先定义 mysqrt(int) 方法(实例方法,public 权限)
public int mysqrt(int x) {
if (x == 0 || x == 1) {
return x;
}
for (int i = 1; i <= x; i++) {
if (i * i == x) {
return i;
} else if (i * i > x) {
return i - 1;
}
}
return 0;
}
// 2. 在 main 方法中实例化 Solution,再调用 mysqrt 方法
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int x = sc.nextInt();
Solution solution = new Solution();
int ret = solution.mysqrt(x);
System.out.println(ret);
sc.close();
}
}