#include <iostream>

using namespace std;

const int num = 39;

int main()
{
    int inp, cal;

    while (cin >> inp) {
        cal = inp % num;
        if (cal == 0)
            cal = num;

        cout << "3C";
        if (cal / 10 == 0)
            cout << "0";
        cout << cal << endl;
    }

    return 0;
}