using System;
using System.Linq;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Point = System.Numerics.Complex;
using Number = System.Int64;
using C = System.Int32;
namespace Program
{
    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            if (2 * n > 2756)
            {
                IO.Printer.Out.WriteLine("Impossible");
                return;
            }
            var s = sc.Scan(n);
            var sat = new TwoSAT(n);

            for (int i = 0; i < n; i++)
                for (int j = i + 1; j < n; j++)
                {
                    var a = s[i].Substring(0, 1);
                    var bc = s[i].Substring(1);

                    var ab = s[i].Substring(0, 2);
                    var c = s[i].Substring(2, 1);

                    var A = s[j].Substring(0, 1);
                    var BC = s[j].Substring(1);

                    var AB = s[j].Substring(0, 2);
                    var C = s[j].Substring(2, 1);

                    //1 & 1 dame
                    if (a == A || bc == BC) sat.NAND(i, j);
                    //0 & 0 dame
                    if (ab == AB || c == C) sat.NAND(sat.NOT(i), sat.NOT(j));
                    //1 & 0 dame
                    if (a == C || bc == AB) sat.NAND(i, sat.NOT(j));
                    //0 & 1 dame
                    if (ab == BC || c == A) sat.NAND(sat.NOT(i), j);
                }
            if (!sat.Satisfy())
            {
                IO.Printer.Out.WriteLine("Impossible");
                return;
            }
            for (int i = 0; i < n; i++)
            {
                if (sat[i])
                    IO.Printer.Out.WriteLine($"{s[i][0]} {s[i][1]}{s[i][2]}");
                else IO.Printer.Out.WriteLine($"{s[i][0]}{s[i][1]} {s[i][2]}");

            }
        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer: StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion

#region 2SAT
/// <summary>
/// 2-SAT
/// </summary>
public class TwoSAT
{
    int n;
    bool finished;
    SCCGraph scc;
    public TwoSAT(int n)
    {
        this.n = n;
        scc = new SCCGraph(2 * n);
    }
    /// <summary>
    /// !v
    /// </summary>
    public int NOT(int v)
    {
        if (v < n) return v + n;
        else return v - n;
    }
    /// <summary>
    /// (a v b) を追加 
    /// </summary>
    public void OR(int a, int b)
    {
        scc.AddEdge(NOT(a), b);
        scc.AddEdge(NOT(b), a);
    }
    /// <summary>
    /// !(avb)を追加
    /// </summary>
    public void NAND(int a, int b)
    {
        OR(NOT(a), NOT(b));
    }
    /// <summary>
    /// a->bを追加
    /// </summary>
    public void IMP(int a, int b)
    {
        scc.AddEdge(a, b);
    }
    public bool Satisfy()
    {
        scc.Build();
        for (int i = 0; i < n; i++)
            if (scc.IsSameGroup(i, NOT(i))) return false;
        finished = true;
        return true;
    }
    public bool this[int v]
    {
        get
        {
            Debug.Assert(0 <= v && v < n && finished);
            return scc.group[v] > scc.group[NOT(v)];
        }
    }

}
#endregion
#region SCCGraph
public class SCCGraph
{
    int n;

    List<int>[] g;

    /// <summary>
    /// 強連結成分内の集合
    /// </summary>
    public List<List<int>> scc;
    /// <summary>
    /// 元のグラフのインデックスから強連結成分分解後のインデックスへの写像
    /// </summary>
    public int[] group;

    /// <summary>
    /// 強連結成分のサイズ
    /// </summary>
    public int size;
    /// <summary>
    /// 強連結成分分解後のグラフ
    /// </summary>
    public List<int>[] G;
    /// <summary>
    /// 強連結成分分解後の自己ループの数
    /// </summary>
    public int[] L;

    public SCCGraph(int N)
    {
        n = N;
        g = new List<int>[n];
        scc = new List<List<int>>();
        for (int i = 0; i < n; i++)
        {
            g[i] = new List<int>();
        }
    }
    public void AddEdge(int f, int t)
    {
        g[f].Add(t);
    }

    /// <summary>
    /// 強連結成分をして，グラフを再構築する
    /// </summary>
    public void Build()
    {
        Decomposite();
        scc.Reverse();
        group = new int[n];
        L = new int[size];
        G = new List<int>[size];
        for (int i = 0; i < size; i++)
        {
            G[i] = new List<int>();
            foreach (var x in scc[i]) group[x] = i;
        }
        for (int i = 0; i < n; i++)
        {
            var u = group[i];
            foreach (var to in g[i])
            {
                var v = group[to];
                if (u == v) L[u]++;
                else G[u].Add(v);

            }

        }

    }
    /// <summary>
    /// 強連結成分分解をする
    /// </summary>
    public int Decomposite()
    {
        var S = new FastStack<int>(n + 2);
        var B = new FastStack<int>(n + 2);
        var I = new int[n];
        var iter = new int[n];
        var s = new FastStack<int>(n + 2);
        for (int i = 0; i < n; i++)
        {
            if (I[i] != 0) continue;
            Debug.WriteLine(i);
            s.Push(i);
            while (s.Any())
            {
                DFS:
                var u = s.Peek();
                if (I[u] == 0)
                {
                    B.Push(I[u] = S.Count);
                    S.Push(u);
                    iter[u] = 0;
                }
                while (iter[u] < g[u].Count)
                {
                    var v = g[u][iter[u]++];
                    if (I[v] == 0)
                    {
                        Debug.WriteLine(v);
                        s.Push(v);
                        goto DFS;
                    }
                    else while (I[v] < B.Peek()) B.Pop();
                }
                if (I[u] == B.Peek())
                {
                    var ns = new List<int>();
                    scc.Add(ns);
                    B.Pop();
                    while (I[u] < S.Count)
                    {
                        var p = S.Pop();
                        ns.Add(p);
                        I[p] = n + scc.Count;
                    }
                }
                s.Pop();

            }
        }
        return size = scc.Count;

    }
    public bool IsSameGroup(int u, int v) { return group[u] == group[v]; }
}
#endregion
#region Stack<T>
public class FastStack<T>
{
    T[] data;
    int ptr;
    public FastStack(int size) { data = new T[size]; }
    public void Push(T item) { data[ptr++] = item; }
    public T Pop() { return data[--ptr]; }
    public T Peek() { return data[ptr - 1]; }
    public bool Any() { return ptr != 0; }
    public T Last { get { return data[ptr - 1]; } set { data[ptr - 1] = value; } }
    public int Count { get { return ptr; } }
}
#endregion