#include<bits/stdc++.h>
using namespace std;
int main(){
    string s,s1;
    int t;
    cin>>s;
    if(s.size()%4==1) s="000"+s;
    else if(s.size()%4==2) s="00"+s;
    else if(s.size()%4==3) s="0"+s;
    for(int i=0;i<s.size();i=i+4){
    	s1=s.substr(i,4);
    	t=(s1[3]-48)*1+(s1[2]-48)*2+(s1[1]-48)*4+(s1[0]-48)*8;
    	if(t>=10){
    		cout<<char (t+55);
    	}
    	else cout<<t; 
    }
	
		
	return 0;	
}
/**************************************************************
	Problem: 1294
	User: chenlingxuan
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2076 kb
****************************************************************/