A wildlife research station fits tracked animals with electronic collars and logs a sighting record every time an animal is detected by a sensor. Each sighting record lists the animal's ID, the ID of the collar device it was wearing at the time, the day number the sighting occurred on, and how many sensor readings were captured during that sighting. An animal may be fitted with a different collar between sightings (for example, after a battery swap), and it is never sighted twice on the same day.

For every animal that appears in the log, the research team wants to know which collar it was wearing on the very first day it was ever sighted — that is, on the sighting with the smallest day number recorded for that animal. The number of sensor readings in a record is logged purely for reference and plays no part in the answer.

Input format

Line 1: an integer m — the number of sighting records. Next m lines: four integers animal_id device_id day readings — one sighting record. For a fixed animal_id, all day values among its records are distinct.

Output format

Print one line per distinct animal_id that appears in the log, in increasing order of animal_id, each formatted as: animal_id device_id — the device_id of the collar recorded on that animal's smallest day.

Constraints

• 1 ≤ m ≤ 2000
• 1 ≤ animal_id, device_id ≤ 100000
• 1 ≤ day ≤ 100000
• 0 ≤ readings ≤ 1000

5
1 101 3 10
1 102 1 15
2 201 2 5
2 202 5 7
3 301 4 2

1 102
2 201
3 301

3
5 555 10 0
2 222 20 100
5 556 5 50

2 222
5 556