include<iostream>
#include<stdio.h>
#include<math.h>
using namespace std;
int main()
{
	int s,v;
	cin>>s>>v;
	int t=0;
	int hour=0,minute=0;
	t=ceil(s/v)+10; 
	if(t>24*60)
	{
		cout<<"error"<<endl; 
		return 0;
 }
	else
	{
		int i=0,j=0;		
		i=t/60;
		j=t%60;
	
		if(8-i<0)
		{
			hour=24-(i+8)-1;
			minute=60-j;			
		}
		else
		{
			hour=8-i-1;
			minute=60-j;
		}
	}
	printf("%02d %c %02d",hour,':',minute);
	return 0;
	
}