#include <stdio.h>
int main()
{
	long long s, v, t, h = 0, m = 0;
	scanf("%d %d", &s, &v);
	t = s / v + 10;
	if (s % v != 0)
		t++;
	h = t / 60, m = t % 60, h = 7 - h, m = 60 - m;
	if (h < 0)
		h += 24;
	if (m == 60)
		m = 0;
	printf("%02lld:", h);
	printf("%02lld", m);
	return 0;
}