package maps;

import java.util.*;

public class StudentAcademy_06 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());

        //студент -> списък от оценките
        Map<String, List<Double>> studentGrades = new LinkedHashMap<>();

        for (int i = 1; i <= n; i++) {
            String studentName = scanner.nextLine();
            double grade = Double.parseDouble(scanner.nextLine());
            //1. имам такъв студент
            if (studentGrades.containsKey(studentName)) {
                List<Double> currentGrades = studentGrades.get(studentName);
                currentGrades.add(grade);
            }
            //2. нямаме такъв студент
            else {
                studentGrades.put(studentName, new ArrayList<>());
                studentGrades.get(studentName).add(grade);
            }
        }


        //студент -> ср. оценка
        //Ivan -> 5.6
        Map<String, Double> studentAverageGrade = new LinkedHashMap<>();
        //студенти със средна оценка >= 4.50

        for (Map.Entry<String, List<Double>> entry : studentGrades.entrySet()) {
            //entry: key(име на студента) -> value (списък с оценки)
            String studentName = entry.getKey();
            List<Double> grades = entry.getValue();
            double averageGrade = getAverageGrade(grades);

            if (averageGrade >= 4.50) {
                studentAverageGrade.put(studentName, averageGrade);
            }
        }

        //print
        //map: key(име на студента) -> value (ср. оценка)
        studentAverageGrade.entrySet().forEach(entry -> System.out.printf("%s -> %.2f%n", entry.getKey(), entry.getValue()));
    }

    private static double getAverageGrade(List<Double> grades) {
        //{5, 4, 6, 2}
        double sum = 0;
        for (double grade : grades) {
            sum += grade;
        }
        return sum / grades.size();
    }
}