#include <algorithm>
#include <deque>
#include <fstream>
#include <sstream>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>

std::string get_string(const std::deque<std::string>& dq) {
    std::stringstream ss;
    for (const auto& str : dq) {
        ss << str;
    }
    return ss.str();
}

int main() {
    std::ifstream in("input.txt");
    std::ofstream out("output.txt");

    size_t word_cnt, row_len;
    in >> word_cnt >> row_len;

    if (word_cnt < row_len) {
        return 0;
    }

    std::unordered_map<std::string, size_t> freq;

    std::deque<std::string> cur_row;

    for (size_t i = 0; i < word_cnt; ++i) {
        std::string word;
        in >> word;
        cur_row.push_back(word);

        auto ss = get_string(cur_row);
        if (i + 1 == row_len) {
            ++freq[get_string(cur_row)];
            cur_row.pop_front();
        }
    }

    std::vector<std::pair<size_t, std::string>> freq_vec;
    for (const auto& [row, times] : freq) {
        freq_vec.push_back({times, row});
    }
    std::sort(freq_vec.begin(), freq_vec.end());
    for (const auto& [times, row] : freq_vec) {

    }
}