Lucky Sum of Digits

2000ms

262144K

Description:

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.

Sample Input:

Sample Output:

Sample Input:

Sample Output:

-1

Informação

Provedor Codeforces

Código CF109A