C :

#include <stdio.h>
#include <malloc.h>
int main()
{ int N;
	while(scanf("%d",&N)!=EOF)
	{int x,count1=0,count2=0,t,i,m,*p;
     while(N--)
	 {
		 scanf("%d",&x);
		 if(!x) count1++;
		 else count2++;
	 }
      t=(count2/9)*9+count1;
	  m=t-count1;
	  p=(int *)malloc(t*sizeof(int));
	  i=t;
	  if(!m&&count1)       printf("0");
	  else if(!count1) printf("-1");
	  else
	  {
	  while(m--)
	  p[--i]=5;	  
	  while(count1--)
      p[--i]=0;
	  for(;t>0;t--)
	  printf("%d",p[t-1]);
	  }
	  printf("\n");
	}
return 0;
}

C++ :

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    int n;
    while(cin>>n)
    {
        int i,temp,count5=0,count0=0;
        while(n--)
        {
            cin>>temp;
            temp?count5++:count0++;
        }
        if(count5<9)
        {
            if(count0>0)
            {
                cout<<"0"<<endl;
                continue;
            }
            cout<<"-1"<<endl;
            continue;
        }
        if(count0==0)
        {
            cout<<"-1"<<endl;
            continue;
        }
        for(i=1;i<=count5/9;i++)
            cout<<"555555555";
        for(i=1;i<=count0;i++)
            cout<<"0";
        cout<<endl;
    }
    return 0;
}