#include <iostream>
#include <fstream>
#include <string>

#define foreach(T,p,c) for(T p = (c).begin(); p != (c).end(); p++)

using namespace std;

string get_string(string &c, int s, int i, int n)
{
	string p = "";
	string::iterator ptr = c.begin() + s;
	int j = 0;

	while(true) {
		p += string(1, *ptr);
		*ptr = '_';
		if(++j >= n) break;

		for(int k = 0; k <= i; k++) {
			while(true) {
				++ptr; if(ptr == c.end()) ptr = c.begin();
				if(*ptr != '_') break;
			}
		}
	}

	return p;
}

bool examine(string c, string p, int s, int i, int n)
{
	string::iterator ptr = c.begin() + s;
	int j = 0;

	while(true) {
		if(*ptr != p[j]) return false;
		*ptr = '_';
		if(++j >= n) return true;

		for(int k = 0; k <= i; k++) {
			while(true) {
				++ptr; if(ptr == c.end()) ptr = c.begin();
				if(*ptr != '_') break;
			}
		}
	}
}

string decrypt(string c)
{
	int m = c.length();
	string p = "";

	for(int n = m / 2; p.empty(); n--) {
		for(int s = 1; s < m; s++) {
			for(int i = 1; i < m; i++) {
				string w = c;
				string q = get_string(w, s, i, n);
				if(p == q) continue;

				bool flag = false;
				for(int t = 1; !flag && t < m; t++) {
					if(c[s] != c[t]) continue;
					for(int j = i + 1; !flag && j < m; j++) {
						flag = examine(w, q, t, j, n);
					}
				}
				if(flag) {
					if(!p.empty()) return "";
					p = q;
				}
			}
		}
	}

	return p;
}

int main(void)
{
	ifstream cin("insecure.in");
	int i = 0;
	string s;
	while(getline(cin, s)) {
		if(s == "X") break;
		string t = decrypt(s);
		cout << "Code " << (++i) << ": "
             << (t == "" ? "Codeword not unique" : t) << endl;
	}
	return 0;
}