백준 2839 Java

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

2839번: 설탕 배달

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import java.util.Scanner;

 
public class Main {
 
	public static void main(String[] args) {
		
		int cnt=0;
		 Scanner scan = new Scanner(System.in);
		 int a=scan.nextInt();
		 scan.close();
		 
		 if(a==4|a==7) {
			 cnt=-1;
		 }
		 else if(a%5==3||a%5==1) {
			 cnt=a/5+1;
		 }
		 else if(a%5==2||a%5==4) {
			 cnt=a/5-2+4;
		 }
		 else if(a%5==0) {
			 cnt=a/5;
		 }
		 System.out.println(cnt);

	}
	
}