use is condition

 if __name__ == '__main__':
n = int(input())
student_marks = {}
for _ in range(n):
    name, *line = input().split()
    scores = list(map(float, line))
    student_marks[name] = scores
query_name = input()
if query_name in student_marks:
    total_marks=sum(student_marks[query_name])/3
    print(f"{total_marks:.2f}")