import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        scanner.nextDouble();
        scanner.nextDouble();
        double length = 0;
        while(scanner.hasNextDouble()) {
            double startX = scanner.nextDouble();
            double startY = scanner.nextDouble();
            double finishX = scanner.nextDouble();
            double finishY = scanner.nextDouble();
            length += Math.sqrt((finishX - startX) * (finishX - startX) + (finishY - startY) * (finishY - startY));
        }
        long minutes = Math.round(3 * length / 500);
        System.out.print(minutes / 60 + ":" + minutes % 60);
    }
}