← 返回题目

题库练习 Lucky Sum of Digits

← 上一题下一题 →

A8199 | $Lucky Sum of Digits$

时间限制1s

内存限制256MB

通过 / 提交0/0

题目描述

Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not. Petya wonders eagerly what minimum lucky number has the sum of digits equal to $n$ . Help him cope with the task.

输入格式

The single line contains an integer $n$ ( $1<=n<=10^{6}$ ) — the sum of digits of the required lucky number.

输出格式

Print on the single line the result — the minimum lucky number, whose sum of digits equals $n$ . If such number does not exist, print -1.

输入输出样例

输入 #1

输出 #1

输入 #2

输出 #2

-1

C++ 编辑器

输入

输出