#include <iostream>
#include <algorithm>
#include <math.h>
#include <vector>
#include <string>
#include <utility>
#include <stdio.h>
#include <queue>
#include <fstream>
#include <functional>
#include <cstdlib>
#include <map>
#include <set>
#include <math.h>
#include <string.h>
#include <stdlib.h>

using namespace std;

typedef pair<int, int> ii ;
typedef vector< ii >   vii ;
typedef vector<int> vi ;
typedef vector<vi> vvi;
typedef pair< int, string > is;

#define pb push_back
#define MAX_N 2000005

int n, printable[MAX_N];
int last[MAX_N];
vector< ii > g[MAX_N];
string sol,maxim;
vector< string > sorted;

bool cmp(const string &a, const string &b ){
    return a.length()>b.length();
}

void dfs(int n){

    for(int i=0;i<g[n].size();i++){
        if(!last[g[n][i].first]){
            sol.pb(char(g[n][i].second+'a'));
            dfs(g[n][i].first);
        }
    }
    for(int i=0;i<g[n].size();i++){
        if(last[g[n][i].first]){
            sol.pb(char(g[n][i].second+'a'));
            dfs(g[n][i].first);
        }
    }

    for(int i=0;i<printable[n];i++)
        sol.pb('P');

    sol.pb('-');
}

void dfsLast(int n, int pos){
    last[n] = 1;
    if(pos == maxim.size())
        return;
    for(int i=0;i<g[n].size();i++){
        if(char(g[n][i].second+'a') == maxim[pos] ){
            dfsLast(g[n][i].first,pos+1);
            break;
        }
    }
}

int main() {

    #ifdef EVAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif

    scanf("%d",&n);
    int maxNode = 0;

    for(int i=0;i<n;i++){
        char t[30]; scanf("%s",t);//cin>>t;
        string temp = t;
        if(temp.length() > maxim.length())
            maxim = temp;
        sorted.pb(temp);
    }

    //sort(sorted.begin(), sorted.end(), cmp);

    for(int i=0;i<n;i++){
        int nodeCurr = 0;
        for(int j=0;j<sorted[i].length();j++){
            int ind = -1 ;
            for(int k=0;k<g[nodeCurr].size();k++)
                if(g[nodeCurr][k].second == sorted[i][j]-'a'){
                    ind = k;
                    break;
                }
            if(ind == -1){
                g[nodeCurr].push_back(make_pair(++maxNode, sorted[i][j]-'a'));
                ind = g[nodeCurr].size()-1;
            }
            if(j == sorted[i].length() - 1)
                printable[maxNode]++;

            nodeCurr = g[nodeCurr][ind].first;

        }
    }
    /*for(int i=0;i<maxNode;i++){
        cout<<i<<": ";
        for(int j=0;j<g[i].size();j++)
            cout<<g[i][j].first<<" "<<char(g[i][j].second+'a')<<endl;
    }*/
    dfsLast(0,0);
    dfs(0);

    int k = sol.length()-1;
    while(sol[k] == '-')
        k--;
    printf("%d\n",k+1);
    for(int i=0;i<=k;i++)
        printf("%c\n",sol[i]);

    return 0;
}

//7 -1 2 -1 5 -2 3 -3 1 1 -1 -2 -1 -3 -4