#include<bits/stdc++.h>
using namespace std;

ifstream in("kps.in");
ofstream out("kps.out");

int main()
{
    string s;
    int t;
    in>>t;
    if(t==1)
    {
        in>>s;
        int k=0;
        string temp1,temp2;
        for(int i=0,j=s.size()-1;i<j;i++,j--)
        {
            temp1+=s[i],temp2+=s[j];
            reverse(temp2.begin(),temp2.end());
            if(temp1==temp2)
                k=temp1.size();
            reverse(temp2.begin(),temp2.end());
        }
        out<<k;
    }
    else
    {
        vector<vector<string>> v(102);
        int maxi=0;
        while(in>>s)
        {
            int k=0;
            string temp1,temp2;
            for(int i=0,j=s.size()-1;i<j;i++,j--)
            {
                temp1+=s[i],temp2+=s[j];
                reverse(temp2.begin(),temp2.end());
                if(temp1==temp2)
                    k=temp1.size();
                reverse(temp2.begin(),temp2.end());
            }
            maxi=max(maxi,k);
            v[k].push_back(s);
        }
        int k=maxi;
        for(int i=0;i<=k;i++)
            sort(v[i].begin(),v[i].end());
        for(int i=0;i<=k;i++)
        {
            out<<v[i].size()<<" ";
            for(int j=0;j<v[i].size();j++)
                out<<v[i][j]<<" ";
            out<<'\n';
        }
    }
}