#include<iostream>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;   
char a[27]={'0','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
vector<char> v;
int main()
{
	int x=2019;
	while(x)
	{
		v.push_back(a[x%26]);
		x/=26;
	}
	reverse(v.begin(),v.end());
	for(auto i:v)cout<<i;
	return 0;
}