Group Word Checker

Interview

Time limit2sMemory limit128 MB

Summary

Count how many of up to 100 lowercase words have every repeated character forming a single contiguous block.

Level: Easy2 of 10
Topics: String, Implementation
Solved: No attempts yet

Problem

A group word is a word where, for every character in the word, all occurrences of that character form one contiguous block. In other words, once a character stops appearing and another character appears, the first character must not appear again later.

For example, ccazzzzbb is a group word because c, a, z, and b each appear in a single contiguous block. kin is also a group word because every character appears only once. However, aabbbccb is not a group word because b appears in two separated blocks.

Given N words, count how many of them are group words.

Input

The first line contains the number of words N. N is a positive integer no greater than 100.

Each of the next N lines contains one distinct word. Every word consists only of lowercase English letters and has length at most 100.

Output

Print the number of group words on the first line.

Examples6

Example 1
Input
```
3
happy
new
year
```
Expected output
```
3
```
Example 2
Input
```
4
aba
abab
abcabc
a
```
Expected output
```
1
```
Example 3
Input
```
5
ab
aa
aca
ba
bb
```
Expected output
```
4
```
Example 4
Input
```
2
yzyzy
zyzyz
```
Expected output
```
0
```
Example 5
Input
```
1
z
```
Expected output
```
1
```

Example 6

Input

9
aaa
aaazbz
babb
aazz
azbz
aabbaa
abacc
aba
zzaz

Expected output