[codeforces] Round #204 (Div. 2) The. Jeff and Digits

October 5, 2013 nguyenvanquan7826 Algorithm, TT Spoj Leave a response
time limit per test 1 second
memory limit per test

256 megabytes

input standard input
output standard output

Jeff’s got n cards, each card contains either digit 0, or digit 5. Jeff can choose several cards and put them in a line so that he gets some number. What is the largest possible number divisible by 90 Jeff can make from the cards he’s got?

Jeff must make the number without leading zero. At that, we assume that number 0 doesn’t contain any leading zeroes. Jeff doesn’t have to use all the cards.

Input

The first line contains integer n (1 ≤ n ≤ 103). The next line contains n integers the1, the2, …, then (thein = 0 or thein = 5). Number thein represents the digit that is written on the in-th card.

Output

In a single line print the answer to the problem — the maximum number, divisible by 90. If you can’t make any divisible by 90 number from the cards, print -1.

Sample test(with)
Input
4
5 0 5 0
Output
0
Input
11
5 5 5 5 5 5 5 5 0 5 5
Output
5555555550
Note

In the first test you can make only one number that is a multiple of 90 - 0.

In the second test you can make number 5555555550, it is a multiple of 90.

Roughly translated summary Threads:

Give 1 integer n (1 ≤ n ≤ 103) and n number one, which one is 0 or 5. Pairing the largest number divisible 90 (Do not count the number 0 at the top). If not, print out -1.

Solution:

+ Count the number of 5 (count5) and the number of 0 (count0).

+ Check that there is some 0 does not? If not, in “-1” and so will not be able to escape divisible 90.

+ Check that the number of 5 < 9 not? If true, then in “0” and drainage

+ If unresolved Print (count5/9)*9 number 5 In some later count0 0 out.