import java.util.*;

public class Main{
  public static void main(String[] args){
    int i;
    Scanner sc = new Scanner(System.in);
    String[] line = sc.next().split(":");
    int[] time = new int[2];
    for(i=0;i<2;i++)time[i] = Integer.parseInt(line[i]);
    time[1] += 5;
    if(time[1]>59){
      time[0]++;
      if(time[0]>23){
        time[0] = 0;
      }
      time[1] = time[1] - 60;
    }
    if(time[0]<10)System.out.print("0");
    System.out.print(time[0] + ":");
    if(time[1]<10)System.out.print("0");
    System.out.println(time[1]);
  }
}