Problems

# Phone List

# Phone List

Given a list of phone numbers, determine if it is consistent in the sense that no number is the prefix of another. Let's say the phone catalog listed these numbers:

- Emergency
**911** - Alice
**97 625 999** - Bob
**91 12 54 26**

In this case, it's not possible to call Bob, because the central would direct your call to the emergency line as soon as you had dialed the first three digits of Bob's phone number. So this list would not be consistent.

#### Input

The first line contains the number of test cases **t** (**1** ≤ **t** ≤ **40**). Each test case starts with the number of phone numbers **n** (**1** ≤ **n** ≤ **1000000**), on a separate line. Then follows **n** lines with one phone number on each line. A phone number is a sequence of at most ten digits.

#### Output

For each test case, output "**YES**" if the list is consistent, or "**NO**" otherwise.

Input example #1

2 3 911 97625999 91125426 5 113 12340 123440 12345 98346

Output example #1

NO YES