Finding the percentage

The provided code stub will read in a dictionary containing key/value pairs of name:[marks] for a list of students. Print the average of the marks array for the student name provided, showing 2 places after the decimal.

Example

The query_name is 'beta'. beta's average score is .

Input Format

The first line contains the integer , the number of students' records. The next lines contain the names and marks obtained by a student, each value separated by a space. The final line contains query_name, the name of a student to query.

Constraints

Output Format

Print one line: The average of the marks obtained by the particular student correct to 2 decimal places.

Sample Input 0

3
Krishna 67 68 69
Arjun 70 98 63
Malika 52 56 60
Malika

Sample Output 0

56.00

Explanation 0

Marks for Malika are whose average is

Sample Input 1

2
Harsh 25 26.5 28
Anurag 26 28 30
Harsh

Sample Output 1

26.50