#include <bits/stdc++.h>
using namespace std;
const int N = 256;
int b[N];

int toDec(char a, char b) {
	int res = 0;
	if (a >= 'A' && a <= 'F')
		res += (a - 'A' + 10) * 16;
	else
		res += (a - '0') * 16;
	if (b >= 'A' && b <= 'F')
		res += b - 'A' + 10;
	else
		res += b - '0' ;
	return res;
}

string toHex(int x) {
	int a = x % 16;
	int b = x / 16;
	char c1, c2;
	if (a >= 10)
		c1 = 'A' + a - 10;
	else
		c1 = a + '0';
	if (b >= 10)
		c2 = 'A' + b - 10;
	else
		c2 = b + '0';
	string res;
	res.push_back(c2);
	res.push_back(c1);
	return res;
}
vector<string>q;

vector<int>vec;

int main() {

	int n;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		string s;
		cin >> s;
		q.push_back(s);
		for (int j = 0; j < s.size(); j += 2) {
			char c1 = s[j], c2 = s[j + 1];
			int k = toDec(c1, c2);
			b[k]++;
		}
	}
	for (int i = 0; i < 16; i++) {
		int mx = 0, mx_id = -1;
		for (int j = 0; j < 256; j++)
			if (b[j] > mx) {
				mx = b[j];
				mx_id = j;
			}
		vec.push_back(mx_id);

		b[mx_id] = -1;
	}
	for (int i = 0; i < min(16, (int)vec.size()); i++)
		cout << toHex(vec[i]) ;
	cout << endl;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < q[0].size(); j += 2) {
			int c1 = q[i][j], c2 = q[i][j + 1];
			int x = toDec(c1, c2);
			int mi = INT_MAX;
			int mi_p = 0;
			for (int k = 0; k < min(16, (int)vec.size()); k++) {
				if (mi > abs(vec[k] - x)) {
					mi = abs(vec[k] - x);
					mi_p = k;
				}
			}
			cout << toHex(mi_p)[1];
		}
		cout << endl;
	}

	return 0;
}