import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
	
	public static long MOD = 1000000007;
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final String[] inputs = sc.next().split(":");
		
		final int hour = Integer.parseInt(inputs[0]);
		final int minute = Integer.parseInt(inputs[1]);
		final long time = hour * 60 + minute;
		
		final long next_hour = ((time + 5) / 60) % 24;
		final long next_minute = (time + 5) % 60;
		
		System.out.printf("%02d:%02d\n", next_hour, next_minute);
		
	}
}