#include <iostream>
#include <queue>
#include <functional>
#include <vector>
using namespace std;
struct node
{
    int prior;
    int w;
    bool occupied;
    node * left;
    node * right;
    node (int val,int priority): prior(priority), w(val), occupied(true), left(NULL), right(NULL) {};
    node (node *l, node *r): prior(l->prior + r->prior), occupied(false), left(l), right(r) {};
};

node * build_tree(string s)
{
    node * l, *r;
    int tab[26]={};
    for (int i=0;i<s.length();i++)
        tab[ s[i] - 'a']++;
    auto f=[](node * a, node *b) {return a->prior >= b->prior;};
    priority_queue <node *, vector<node*>, decltype(f)> Q (f);
    for (int i=0;i<26;i++)
        if (tab[i]!=0)
            Q.push(new node (i,tab[i]));
    while (Q.size()>1)
    {
        l=Q.top();
        Q.pop();
        r=Q.top();
        Q.pop();
        Q.push(new node(l,r));
    }
    return Q.top();
}

//UTILITY:

void save (node * p, string * tab, string ind)
{
    if (p==NULL) return;
    if (p->occupied)
        tab[p->w]=ind;
    save(p->left,tab,ind+'0');
    save(p->right,tab,ind+'1');
}
string * kody(string s)
{
    node * p= build_tree(s);

    string * tab=new string [26];
    for (int i=0;i<26;i++) tab[i]="empty";
    save(p,tab,"");
    return tab;
}
int main ()
{
    string input;
    string * tab;
    cin >> input;
    tab=kody(input);
    for (int i=0;i<26;i++)
        if (tab[i]!="empty")
            cout << "litera: " <<(char) (i+'a') << " kod: " << tab[i] << endl;
    return 0;
}