#include <iostream>

using namespace std;

void solve()
{
	int n;
	while(cin >> n)
	{
		cout << "3C";
		int ans = n % 39;
		if(ans < 10)
		{
			if(ans == 0)
			{
				cout << "39" << endl;
			}
			else
			{
				cout << "0" << ans << endl;
			}
		}
		else
		{
			cout << ans << endl;
		}
	}
}

int main()
{
	solve();
	return(0);
}