#include <iostream>

using namespace std;
void f(long n)
{
 if (n!=0)
 {
  if (n%2==0)
   {
   cout<<n%10;
   }
  f(n/10);
  if (n%2!=0)
  {
    cout<<n%10;
  }
 }
  else
 {
    cout<<endl;
 }
}
int main()
{long n;
    cout <<"N=";cin>>n;
    f(n);
    return 0;
}










#include <iostream>

using namespace std;
void f (int b)
{
 if(3<=b)
 {
    f(b-2);
    cout<<'*';
 }
  else
 {
    cout<<b;
 }
}
int main()
{int b;
    cout <<"B=";cin>>b;
    f(b);
    return 0;
}







#include <iostream>

using namespace std;
int f (int n)
{
 int c;
  if (n!=0)
  {
    if (n%2==1)
     {
          c=1+f(n/2);
     }
     else
     {
         c=f(n/2);
     }
   cout<<n%2;
   return c;
  }
   else
  {
    return 0;
  }
}
int main()
{int n;
    cout<<"N=";cin>>n;
    cout <<f(n);
    return 0;
}