Fleet Diagnostic Watchlist

A logistics operator tracks a fleet of delivery drones. After each flight, every drone uploads a short diagnostic report: an identifier, a call name, and a list of diagnostic codes produced by its onboard sensors. The maintenance team wants to build a watchlist of every drone that reported at least one diagnostic code beginning with a specific alert prefix, so a technician can inspect it before the drone flies again.

Given the fleet's reports and an alert prefix, output the identifier and call name of every drone that has at least one diagnostic code starting with that prefix (a code counts as a match as soon as its leading characters equal the prefix, even if the code continues further — e.g. code OVH104 matches prefix OVH1). Preserve the order in which drones appear in the input.

Input format

• Line 1: a single integer n, the number of drones.
• Line 2: the alert prefix, a string of uppercase letters and digits.
• The next n lines each describe one drone: an identifier, a call name, an integer k (the number of diagnostic codes that drone reported), and then k diagnostic codes — all separated by single spaces.

Output format

• First line: a single integer m, the number of drones on the watchlist.
• The next m lines: for each flagged drone, in the same order it appeared in the input, print its identifier and call name separated by a single space.

Constraints

• 1 <= n <= 1000
• 1 <= length of the alert prefix <= 20, consisting only of uppercase letters (A-Z) and digits (0-9)
• Each identifier is an integer between 1 and 10^9 (identifiers need not be unique)
• Each call name has length between 1 and 30 and consists of uppercase or lowercase letters, digits, and underscores only (no spaces)
• 0 <= k <= 20 for every drone
• Each diagnostic code has length between 1 and 20 and consists only of uppercase letters and digits

3
OVH1
101 DRN_A 2 OVH104 GPS02
102 DRN_B 1 BAT7
103 DRN_C 3 OVH204 OVH1X ROT3

2
101 DRN_A
103 DRN_C

2
ZED
5 UNIT5 0
6 UNIT6 2 ERR90 ERR8

0