b16_rec

#include <iostream>
using namespace std;

char baza[]="0123456789ABCDEF";
void generare (unsigned int n,int p)
{
    if(n)
       generare(n/16, p*16),cout<<baza[n%16];
}

int main()
{
    unsigned int n;
    cin>>n;
    generare(n,1);
    return 0;
}