please tell what is case 13?

and my code given below.

#include <iostream>

using namespace std;

int c[10];
bool reply;
int main() {
    int t;
    cin>>t;
    int in=t;
    if(!t) cout<<10;
    else if(t==1) cout<<1;
    else {
        for(int i=9;i>1;i--) {
            if(i==in) continue;
            while(!(t%i)) {
                t/=i;
                c[i]++;
            }
        }
        for(int i=2;i<10;i++) {
            if(c[i]) reply=1;
        }
        if(t>1) reply=0;
        if (reply) {
            for(int i=2;i<10;i++) {
                while(c[i]--) cout<<i;
            }
        }
        else cout<<-1;
    }
}