#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <cmath>
//#include<bits/stdc++.h>
//#define int long long
#define pb push_back
using namespace std;
bool isInt(char a)
{
    for(int i = 0; i < 10; i++)
        if(a - '0' == i)
            return true;
    return false;
}
signed main()
{
    int t;
    cin >> t;
    vector<string> schools,ans;
    while(t--)
    {
        string s;
        string str="";
        getline(cin,s);
        for(auto i: s)
            if(isInt(i))
                str+=i;
        schools.pb(str);
    }
    int cnt = 1;
    sort(schools.begin(),schools.end());
    for(int i = 1; i < schools.size(); i++)
    {
        if(schools[i-1] == schools[i])
            cnt++;
        else
        {
            if(cnt <= 5)
                ans.pb(schools[i-1]);
            cnt = 1;
        }
    }
    cout << ans.size() << "\n";
    for(auto i: ans)
        cout << i << "\n";
}