Log Stream Analysis

Description:

Input:

The first line of the input contains two space-separated integers n and m (1 ≤ n, m ≤ 10000).

The second and the remaining lines of the input represent the log stream. The second line of the input contains the first record of the log stream, the third line contains the second record and so on. Each record of the log stream has the above described format. All records are given in the chronological order, that is, the warning records are given in the order, in which the warnings appeared in the program.

It is guaranteed that the log has at least one record. It is guaranteed that the total length of all lines of the log stream doesn't exceed 5·10⁶ (in particular, this means that the length of some line does not exceed 5·10⁶ characters). It is guaranteed that all given dates and times are correct, and the string 'MESSAGE" in all records is non-empty.

Output:

If there is no sought moment of time, print -1. Otherwise print a string in the format "2012-MM-DD HH:MM:SS" (without the quotes) — the first moment of time when the number of warnings for the last n seconds got no less than m.

Sample Input:

60 3
2012-03-16 16:15:25: Disk size is
2012-03-16 16:15:25: Network failute
2012-03-16 16:16:29: Cant write varlog
2012-03-16 16:16:42: Unable to start process
2012-03-16 16:16:43: Disk size is too small
2012-03-16 16:16:53: Timeout detected

Sample Output:

2012-03-16 16:16:43

Sample Input:

1 2
2012-03-16 23:59:59:Disk size
2012-03-17 00:00:00: Network
2012-03-17 00:00:01:Cant write varlog

Sample Output:

-1

Sample Input:

2 2
2012-03-16 23:59:59:Disk size is too sm
2012-03-17 00:00:00:Network failute dete
2012-03-17 00:00:01:Cant write varlogmysq

Sample Output:

2012-03-17 00:00:00