P1100 [CF109A] Lucky Sum of Digits
入门
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.

Input

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

Output

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.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
11
样例输出
47