package main

import (
	"fmt"
	"strconv"
	"strings"
)

func changeHour(hour, minutes *int) {
	*minutes += 5
	if *minutes >= 60 {
		*hour += 1
		*minutes -= 60
	}
	if *hour == 24 {
		*hour = 0
	}
}

func intToStoring(num *int) {
	if *num < 10 {
		fmt.Printf("0%d", *num)
	} else {
		fmt.Printf("%d", *num)
	}
}

func main() {
	var num string
	fmt.Scan(&num)
	list := strings.Split(num, ":")
	hour, _ := strconv.Atoi(list[0])
	minutes, _ := strconv.Atoi(list[1])
	changeHour(&hour, &minutes)
	intToStoring(&hour)
	fmt.Print(":")
	intToStoring(&minutes)
}