백준 7단계 no.7

import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int m = sc.nextInt();
        int min = 0;
        int x = 0;
        int y = 0;

        for (; 5 * x <= m; x++) {
            for (; 5 * x + 3 * y <= m; y++) {
                if ((5 * x + 3 * y) == m) {
                    min = x + y;
                }
            }
            y = 0;
        }

        if (min == 0) {
            System.out.println(-1);
        } else {
            System.out.println(min);
        }
    }
}