#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;
}