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CodeForces 109A Lucky Sum of D

[编程题]CodeForces 109A Lucky Sum of D
  • 热度指数:11 时间限制:C/C++ 2秒,其他语言4秒 空间限制:C/C++ 256M,其他语言512M
  • 算法知识视频讲解

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.


输入描述:

The single line contains an integer n (1 ≤ n ≤ 106) — the sum of digits of the required lucky number.



输出描述:

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.

示例1

输入

11<br />10<br />

输出

47<br />-1<br />

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