// @Title: 灯泡开关 (Bulb Switcher)
// @Author: qisiii
// @Date: 2021-11-15 15:22:28
// @Runtime: 0 ms
// @Memory: 34.8 MB
// @comment: 
// @flag: 
class Solution {
    public int bulbSwitch(int n) {
        return (int) Math.sqrt(n);
    }
}