B

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B - Jeff and Digits
Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u
Submit Status Practice CodeForces 352A

Description

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 a1a2...an (ai = 0 or ai = 5). Number airepresents the digit that is written on the i-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 Input

Input
45 0 5 0
Output
0
Input
115 5 5 5 5 5 5 5 0 5 5
Output
5555555550
当9的倍数个5时,能被9整除,被90 整除,就必须有0;
结论性数论题
#include<stdio.h>
int main()
{
int n,a,b,p,d,i;
while(~scanf("%d",&n))
{
a=0;
b=0;
for( i=0;i<n;i++)
{
 scanf("%d",&d);
 if(d==5)a++;
 if(d==0)b++;
}
p=a/9;
if(b==0)printf("-1\n");
else 
{
if(p==0)printf("0");
else
{
for(i=0;i<p*9;i++)
     printf("5");
     for(i=0;i<b;i++)
     printf("0");
     }
     printf("\n");


 }

}
0 0
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