AC代码(大坑:1*0 = 0)
#include <iostream>
#include <bits/stdc++.h>
using namespace std;
int main()
{
long long int q;
int i, a[120], h;
while(cin>>q)
{
if(q==1)
cout<<1<<endl;
else if(q==0)
cout<<10<<endl;
else
{
h = 0;
memset(a, 0, sizeof(a));
for(i = 9; i>1; i--)
{
while(q%i==0)
{
a[h++] = i;
q = q/i;
}
}
if(q>10)
cout<<-1<<endl;
else
{
if(q!=1)
a[h++] = q;
sort(a, a+h);
for(i = 0;i<h;i++)
cout<<a[i];
printf("\n");
}
}
}
return 0;
}