import java.util.*;
import java.io.*;
import java.text.*;
//Solution Credits: Taranpreet Singh
public class Main{
    //SOLUTION BEGIN
    void pre() throws Exception{}
    void solve(int TC) throws Exception{
        int n = ni(), m = n*n-n;
        MyTreeSet<String> set = new MyTreeSet<>(new Comparator<String>(){
            public int compare(String s1, String s2){
                if(s1.length()!=s2.length())return Integer.compare(s1.length(), s2.length());
                return s1.compareTo(s2);
            }
        });
        for(int i = 0; i< m; i++)set.add(n());
        String s1 = set.first();
        for(int i = 1; i< s1.length(); i++){
            MyTreeSet<String> tmp = new MyTreeSet<>(new Comparator<String>(){
                public int compare(String s1, String s2){
                    if(s1.length()!=s2.length())return Integer.compare(s1.length(), s2.length());
                    return s1.compareTo(s2);
                }
            });
            for(Map.Entry<String, Integer> e:set.map.entrySet())tmp.map.put(e.getKey(), e.getValue());
            String[] ans = check(n, tmp, s1.substring(0, i));
            if(ans!= null){print(ans);return;}
        }
        for(int i = s1.length()-1; i>= s1.length()/2; i--){
            MyTreeSet<String> tmp = new MyTreeSet<>(new Comparator<String>(){
                public int compare(String s1, String s2){
                    if(s1.length()!=s2.length())return Integer.compare(s1.length(), s2.length());
                    return s1.compareTo(s2);
                }
            });
            for(Map.Entry<String, Integer> e:set.map.entrySet())tmp.map.put(e.getKey(), e.getValue());
            String[] ans = check(n, tmp, s1.substring(i));
            if(ans!=null){print(ans);return;}
        }
        pn("No");
    }
    String[] check(int n, MyTreeSet<String> set, String s){
        String[] ans = new String[n];
        ans[0] = s;
        boolean f = true;
        for(int i = 1; i< n && f; i++){
            String s1 = set.first();
            MyTreeSet<String> cand = new MyTreeSet<>();
            if(s1.startsWith(s))cand.add(s1.substring(s.length()));
            if(s1.endsWith(s))cand.add(s1.substring(0, s1.length()-s.length()));
            boolean x = false;
            for(Map.Entry<String, Integer> e:cand.map.entrySet()){
                String cur = e.getKey();
                if(set.contains(s+cur) && set.contains(cur+s)){
                    ans[i] = cur;
                    for(int j = 0; j< i; j++){
                        f &= set.remove(cur+ans[j]);
                        f &= set.remove(ans[j]+cur);
                    }
                    x = true;
                    break;
                }
            }
            if(!x)f = false;
        }
        return f?ans:null;
    }
    void print(String[] ar){
        pn("Yes");
        for(String s:ar)pn(s);
    }
    class MyTreeSet<T>{
        private int size;
        private TreeMap<T, Integer> map;
        public MyTreeSet(){
            size = 0;
            map = new TreeMap<>();
        }
        public MyTreeSet(Comparator<T> t){
            size = 0;
            map = new TreeMap<>(t);
        }
        public int size(){return size;}
        public int dsize(){return map.size();}
        public boolean isEmpty(){return size==0;}
        public void add(T t){
            size++;
            map.put(t, map.getOrDefault(t, 0)+1);
        }
        public boolean remove(T t){
            if(!map.containsKey(t))return false;
            size--;
            int c = map.get(t);
            if(c==1)map.remove(t);
            else map.put(t, c-1);
            return true;
        }
        public int freq(T t){return map.getOrDefault(t, 0);}
        public boolean contains(T t){return map.getOrDefault(t,0)>0;}
        public T ceiling(T t){return map.ceilingKey(t);}
        public T floor(T t){return map.floorKey(t);}
        public T first(){return map.firstKey();}
        public T last(){return map.lastKey();}
    }
    //SOLUTION END
    void hold(boolean b)throws Exception{if(!b)throw new Exception("Hold right there, Sparky!");}
    long mod = (long)1e9+7, IINF = (long)1e10;
    final int INF = (int)1e9, MX = (int)1e4+1;
    DecimalFormat df = new DecimalFormat("0.00000000000");
    double PI = 3.1415926535897932384626433832792884197169399375105820974944, eps = 1e-8;
    static boolean multipleTC = false, memory = false;
    FastReader in;PrintWriter out;
    void run() throws Exception{
        in = new FastReader();
        out = new PrintWriter(System.out);
        int T = (multipleTC)?ni():1;
        //Solution Credits: Taranpreet Singh
        pre();for(int t = 1; t<= T; t++)solve(t);
        out.flush();
        out.close();
    }
    public static void main(String[] args) throws Exception{
        if(memory)new Thread(null, new Runnable() {public void run(){try{new Main().run();}catch(Exception e){e.printStackTrace();}}}, "1", 1 << 28).start();
        else new Main().run();
    }
    long gcd(long a, long b){return (b==0)?a:gcd(b,a%b);}
    int gcd(int a, int b){return (b==0)?a:gcd(b,a%b);}
    int bit(long n){return (n==0)?0:(1+bit(n&(n-1)));}
    void p(Object o){out.print(o);}
    void pn(Object o){out.println(o);}
    void pni(Object o){out.println(o);out.flush();}
    String n()throws Exception{return in.next();}
    String nln()throws Exception{return in.nextLine();}
    int ni()throws Exception{return Integer.parseInt(in.next());}
    long nl()throws Exception{return Long.parseLong(in.next());}
    double nd()throws Exception{return Double.parseDouble(in.next());}

    class FastReader{
        BufferedReader br;
        StringTokenizer st;
        public FastReader(){
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        public FastReader(String s) throws Exception{
            br = new BufferedReader(new FileReader(s));
        }

        String next() throws Exception{
            while (st == null || !st.hasMoreElements()){
                try{
                    st = new StringTokenizer(br.readLine());
                }catch (IOException  e){
                    throw new Exception(e.toString());
                }
            }
            return st.nextToken();
        }

        String nextLine() throws Exception{
            String str = "";
            try{   
                str = br.readLine();
            }catch (IOException e){
                throw new Exception(e.toString());
            }  
            return str;
        }
    }
}