993

Solution:

#include <iostream>
#include <vector>

using namespace std;

int main()
{
int t,c;
long long int n;
vector<long long int> v;

cin>>t;
while(t--)
{
cin>>n;
if(n<=9)
{
cout<<n<<"\n";
continue;
}
while(n>=10)
{
v.clear();
c=0;
for(long long int i=9;i>=2;i--)
{
if(n%i==0)
{
c=1;
n/=i;
v.push_back(i);
break;
}
}
if(n<10)
{
v.push_back(n);
break;
}
if(c==0)
{
v.clear();
cout<<"-1\n";
break;
}
}
if(v.size()==0)
continue;
for(int i=v.size()-1;i>=0;i--)
cout<<v[i];
cout<<"\n";
}

return 0;
}