It's hard for Hong to find the longest common substring of N different strings. Hong wants you to solve this question.

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It's hard for Hong to find the longest common substring of N different strings. Hong wants you to solve this question.

The first line will be an integer T (1≤T≤10), which is the number of test cases.

For each test data:

The first line contains an integer N (1≤N≤1000) — the number of the sentences.

Each of the next N lines contains a string s, which consists of lowercase letters (no space) only. The length of each string will be at least 1 and at most 200 characters.

For each case please print the lexicographically smallest longest common substring. If there is no such non-empty string, output the words “Hong” instead.

```
1
3
aabbaabb
abbababb
bbbbbabb
```

```
abb
```