package main

import (
	"bufio"
	"fmt"
	"os"
	"regexp"
	"time"
)

func ParseData(pointer *[]string) {
	re := regexp.MustCompile(`\d+:\d+`)
	timeStringLayout := "15:04"
	dataLen := len(*pointer)
	for i := 0; i < dataLen; i++ {
		// address := &(*pointer)[i]
		// fmt.Printf("Element %d: Value = %s, Address = %p\n", i, *address, address)
		if i == 0 {
			continue
		}

		// fmt.Println((*pointer)[i])
		startTime := re.Find([]byte((*pointer)[i-1]))
		startTimeString := string(startTime)
		startTimeParsed, err := time.Parse(timeStringLayout, startTimeString)
		if err != nil {
			fmt.Println("Error parsing date:", err)
		}
		endTime := re.Find([]byte((*pointer)[i]))
		endTimeString := string(endTime)
		// fmt.Printf("%s - %s\n", startTime, endTime)
		endTimeParsed, err := time.Parse(timeStringLayout, endTimeString)
		if err != nil {
			fmt.Println("Error parsing date:", err)
		}
		duration := endTimeParsed.Sub(startTimeParsed)
		fmt.Printf("%s\t%s\n", duration, (*pointer)[i])
	}
}

func main() {
	// Create a new scanner to read from standard input
	scanner := bufio.NewScanner(os.Stdin)

	// Create var for string array with received data
	var dataToParse []string

	// Read each line from stdin
	for scanner.Scan() {
		line := scanner.Text()
		// Process the line (for example, print it)
		dataToParse = append(dataToParse, line)
	}

	// Check for errors during scanning
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "Error reading from stdin:", err)
	}
	// for i := 0; i < len(dataToParse); i++ {
	// 	fmt.Println(dataToParse[i])
	// }
	ParseData(&dataToParse)
}