Juggling Letters

题意翻译

给定 $n$ 个由小写字母构成的字符串 $s_1,s_2,...,s_n$ 。 你可以进行以下操作（次数不限）： 将字符串 $s_i$ 的任意字符移动至 $s_j$ 的任意位置（注意 $i$ 可能等于 $j$ ）。 问是否可以让所有字符串相同？若可以，输出```YES```，否则输出```NO```。

题目描述

You are given $ n $ strings $ s_1, s_2, \ldots, s_n $ consisting of lowercase Latin letters. In one operation you can remove a character from a string $ s_i $ and insert it to an arbitrary position in a string $ s_j $ ( $ j $ may be equal to $ i $ ). You may perform this operation any number of times. Is it possible to make all $ n $ strings equal?

输入输出格式

输入格式

The first line contains $ t $ ( $ 1 \le t \le 10 $ ): the number of test cases. The first line of each test case contains a single integer $ n $ ( $ 1 \le n \le 1000 $ ): the number of strings. $ n $ lines follow, the $ i $ -th line contains $ s_i $ ( $ 1 \le \lvert s_i \rvert \le 1000 $ ). The sum of lengths of all strings in all test cases does not exceed $ 1000 $ .

输出格式

If it is possible to make the strings equal, print "YES" (without quotes). Otherwise, print "NO" (without quotes). You can output each character in either lowercase or uppercase.

输入输出样例

输入样例 #1

4
2
caa
cbb
3
cba
cba
cbb
4
ccab
cbac
bca
acbcc
4
acb
caf
c
cbafc

输出样例 #1

YES
NO
YES
NO

说明

In the first test case, you can do the following: - Remove the third character of the first string and insert it after the second character of the second string, making the two strings "ca" and "cbab" respectively. - Remove the second character of the second string and insert it after the second character of the first string, making both strings equal to "cab". In the second test case, it is impossible to make all $ n $ strings equal.