#include <stdio.h>

int main()
{
	int s, v;
	int h, min;
	
	scanf("%d %d", &s, &v);
	
	h = s/(60*v);
	if(s%v == 0)
	{
		min = s/v%60;
	}
	else
	{
		min = s/v%60 + 1;
	}
	
	if(min + 10 >= 60)
	{
		min = min - 60;
		h = h + 1;
	}
	else
	{
		min = min + 10;
	}
	if(h >= 8)
	{
		if(min == 0)
		{
			if(h == 8)
			{
				h = 0;
			}
			else
			{
				h = 32 - h;	
			} 
		}
		else
		{
			h = 31 - h;
			min = 60 - min;
		}
	}
	else
	{
		if(min == 0)
		{
			h = 8 - h;
		}
		else
		{
			h = 7 - h;
			min = 60 - min;
		}
	}
	
	printf("%02d:%02d", h, min);
}