Problem E
Vefþjónatjón
Languages
en
is
A web server needs three pieces to work: a CPU, memory and a hard drive. If one or more of these are missing, the web server won’t work.
Bjarki had the idea that he could take parts from some of the servers and put them into others. For example if one webserver has a CPU and hard drive, but no memory, he could take the memory from a different web server to make this one work. Bjarki started to wonder how many web servers he could get going by doing this.
Could you help Bjarki figure out how many webservers he can set up if he gives you a list of web servers and what parts are missing from each?
Input
The first line contains an integer $n$, the number of web servers Bjarki
has.
The next $n$ lines each
contain a description of a web server, each line containing
three letters which are either “J” or “N”.
The first letter in line $i$ denotes whether there is a CPU in
web server number $i$,
second letter denotes whether there is memory present in web
server $i$ and finally the
third denotes whether there is a hard drive in web server
$i$. “J” denotes that the
component is present while “N” denotes that it is not
present.
Output
Print the maximum number of web servers Bjarki can get going.
Scoring
|
Group |
Points |
Constraints |
|
1 |
50 |
$1 \leq n \leq 1000$ |
|
2 |
50 |
$1 \leq n \leq 10^5$ |
| Sample Input 1 | Sample Output 1 |
|---|---|
2 J J N N N J |
1 |
| Sample Input 2 | Sample Output 2 |
|---|---|
3 J N N N J N N N J |
1 |
