[Baekjoon Online Judge] 2839 - 설탕 배달 / Java

https://www.acmicpc.net/problem/2839

2839번: 설탕 배달

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		int N = Integer.parseInt(br.readLine());

		int answer = 0;

		while (true) {
			if (N % 5 == 0) {
				System.out.println(N / 5 + answer);
				break;
			} else if (N <= 0) {
				System.out.println(-1);
				break;
			}
			N = N - 3;
			answer++;
		}
	}
}