#include <iostream>
#include <cstdio>
#include <set>

using namespace std;

const int N = 100010;

int n;
string s[N];

/**
 * 1.n>=53肯定无解，单个字母重复
 * 2.2_SAT???
 */

int main() {
    // freopen("st.in", "r", stdin);
    // freopen("st.out", "w", stdout);

    scanf("%d", &n);
    for (int i = 0; i < n; ++i) cin >> s[i];

    if (n >= 53) {
        puts("Impossible");
        return 0;
    } else {
        bool flag = false;
        set<string> ss;
        for (int i = 0; i < 1 << n; ++i) {
            ss.clear();
            bool ok = true;
            for (int j = 0; j < n; ++j) {
                string a, b;
                if (i >> j & 1) {
                    a = s[j].substr(0, 1);
                    b = s[j].substr(1, 2);
                } else {
                    a = s[j].substr(0, 2);
                    b = s[j].substr(2, 1);
                }
                if (ss.count(a) || ss.count(b)) {
                    ok = false;
                    break;
                }
                ss.insert(a);
                ss.insert(b);
            }
            if (ok) {
                for (int j = 0; j < n; ++j) {
                    if (i >> j & 1) {
                        cout << s[j][0] << ' ' << s[j][1] << s[j][2] << endl;
                    } else {
                        cout << s[j][0] << s[j][1] << ' ' << s[j][2] << endl;
                    }
                }
                flag = true;
                break;
            }
        }
        if (!flag) {
            puts("Impossible");
        }
    }
    
    return 0;
}