ICQ#443
In a school, each student has a unique ICQ number. It is believed that the smaller the ICQ number, the more advanced the student is. You are given a list of all students and their ICQ numbers. Output the names of the most advanced students.
The first line contains two integers (1 \leq N \leq 100) and (1 \leq K \leq N).
Each of the next lines contains a student's surname (no spaces, at most lowercase Latin letters) followed by their ICQ number (1 \leq \text{ICQ} \leq 10^9), separated by a space. All ICQ numbers and surnames are unique.
Output the surnames of the most advanced students in lexicographical (alphabetical) order, each on a separate line.
Example 1