#include <iostream>
#include <map>
#include <vector>
#include <algorithm>
#include <string>
#include <cctype>

using namespace std;

bool comparePairs(
    const pair<string, int>& i0,
    const pair<string, int>& i1
);

int main() {
    map<string, int> words;
    string word;
    bool readingWord = false;
    while (true) {
        // char c;
        // cin >> c;
        string line;
        std::getline(cin, line);
        if (!cin.good())
            break;
        for (size_t i = 0; i < line.size(); ++i) {    
            char c = line[i];
            if (readingWord) {
                if (isalnum(c) || c == '_') {
                    word += c;
                } else {
                    // End of current word
                    readingWord = false;
                    if (words.count(word) == 0) {
                        // Add a word to the dictionary
                        words[word] = 1;
                    } else {
                        // Increment the number of such words in a text
                        ++(words[word]);
                    }
                    // cout << word << endl;
                }
            } else {
                if (isalpha(c) || c == '_') {
                    word.clear();
                    word += c;
                    readingWord = true;
                }
            }    
        } // end for
    } // end while
    
    // Print words in alphabet lexicographic order        
    vector< pair<string, int> > wordFreq;
    for (auto i = words.cbegin(); i != words.cend(); ++i) {
        // cout << i->first << " " << i->second << endl;
        wordFreq.push_back(*i);
    }
    cout << "Number of different words in a text: " << wordFreq.size() << endl;                
                    
    stable_sort(wordFreq.begin(), wordFreq.end(), comparePairs);
    for (auto i = wordFreq.cbegin(); i != wordFreq.cend(); ++i) {
        cout << i->second << "\t" << i->first << endl;
    }

    return 0;
}                
                    
bool comparePairs(
    const pair<string, int>& i0,
    const pair<string, int>& i1
) {
    return (i0.second > i1.second);
}