#include<stdio.h>
int main()
{
	int s, v, t, h, min, h1, min1;
	float t1;
	scanf("%d %d", &s, &v);
	t = s / v;
	t1 = float(s) / v;
	if (t1 - t != 0)
		t++;
	if (t > 8 * 60)
	{
		h1 = t / 60;
		min1 = t % 60+10;
		if (min1 > 0)
		{
			h = 31 - h1;
			min = 60 - min1;
		}
		else if (min1 == 0)
		{
			h = 32 - h1;
			min = min1;
		}
	}
	else
	{
		h1 = t / 60;
		min1 = t % 60 + 10;
		if (min1 > 0)
		{
			h = 7 - h1;
			min = 60 - min1;
		}
		else if (min1 == 0)
		{
			h = 8 - h1;
			min = min1;
		}
	}
	printf("%02d:%02d\n", h, min);
	return 0;
}

有没有大神救救孩子