题目描述
Not to be confused with chessboard.
Input
The first line of input contains a single integer N (1 ≤ N ≤ 100) — the number of cheeses you have.
The next N lines describe the cheeses you have. Each line contains two space-separated strings: the name of the cheese and its type. The name is a string of lowercase English letters between 1 and 10 characters long. The type is either "soft" or "hard. All cheese names are distinct.
Output
Output a single number.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
9
brie soft
camembert soft
feta soft
goat soft
muenster soft
asiago hard
cheddar hard
gouda hard
swiss hard
样例输出
3