백준 Java 2292번 : 벌집

https://www.acmicpc.net/problem/2292

2292번: 벌집

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import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		int a = sc.nextInt();
		int num = 1;
		int range = 2;
		
		if(a == 1) {
			System.out.println(1);
		} else {
			while(range <= a) {
				range = range + (6 * num);
				num++;
			}
			System.out.println(num);
		}
	}
}