#include <iostream>

using namespace std;

int main()
{
int n,k,b;
cin>>b;
n=0;
k=b;
do{
    n=n+1;
    b=b/16;
}while(b);
b=k;
int a[n];
for (int i=1;i<=n-1;i++){
    a[i]=b%16;
    b=b/16;
}
a[n]=b;
for (int i=n;i>=1;i--){
    switch(a[i]){
    case 10:cout<<"A";
                  break;
    case 11:cout<<"B";break;
    case 12:cout<<"C";break;
    case 13:cout<<"D";break;
    case 14:cout<<"E";break;
    case 15:cout<<"F";break;
    default:
    cout<<a[i];
    }
}
}