pr1b.tema

#include<iostream>
using namespace std;
int main ()
{
    int x,x2=0,p=1,cif;

    cin>>x;

    do
    {
         cif=x%10;
        if(cif==2 || cif==3  || cif==5 || cif==7)
        {
            x2=x2+x%10*p;
            p=p*10;
        }
        else
        {
            x2=x2;
        }
        x=x/10;
    } while(x!=0);
    cout<<x2;
    return 0;
}