#include <iostream>
#include <stdio.h>
using namespace std;
int main(){
	int n;
	while(scanf("%d",&n) != EOF){
		cout<<"3C";
		if(n%39==0) cout<<"39"<<endl;
		else if(n%39<10 && n%39>0) cout<<"0"<<n%39<<endl;
		else cout<<n%39<<endl;
	}
	return 0;
}