import java.util.Scanner;

class Main{

	public static void main(String[]$) {
		Scanner s=new Scanner(System.in);
		int t=900+s.nextInt()*60+s.nextInt()
		+(int)(Double.parseDouble(s.next().substring(3))*60);
		t%=1440;
		System.out.printf("%02d:%02d\n",t/60,t%60);
	}
}