#include<bits/stdc++.h>
#include <iostream>
#include <string>
#include <ctime>
#include <cstdio>
#include <iomanip> 
#include <cmath>
#include <vector>
#include <algorithm>

using namespace std;

void name1 ( int a , int b )
{
	
}

struct name2
{
	
};

int main()
{

	string str;
    getline(cin, str); // 使用 std::getline 来读取整行输入

    vector<string> substrings;
    for (size_t i = 0; i < str.length() - 1; ++i) {
        substrings.push_back(str.substr(i, 2));
    }

    std::sort(substrings.begin(), substrings.end());
    
    for (const string& substring : substrings) {
        cout << substring << std::endl;
    }



	system("pause");
	
	return 0;
}