// #define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <cmath>
#include <cstdlib>
#include <functional>
#include <locale>
#include <cctype>
#include <sstream>	// istringstream
using namespace std;

typedef long long LL;
typedef vector<int> VI;
typedef vector<VI> VVI;

#define MP make_pair
#define fastIO	cin.tie(0); ios::sync_with_stdio(false);
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
//for gcc (未test)
// #define FOREACH_IT(it,c)	for(typeof(c)::iterator it=(c).begin(); it!=(c).end(); ++it)
//for Visual Studio
#define foreach_it(type,it,c) for(type::iterator it=c.begin(); it!=c.end(); ++it)

int main(){
	int n, ans = 0;
	while (cin >> n){
		ans = n % 39;
		if (ans == 0)	ans = 39;
		printf("3C%02d\n", ans);
	}
	return 0;
}