#pragma warning(disable:4996)
#include<stdio.h>
#include<string.h>
#include<math.h>

int main()
{
	int s, v, t = 0;
	scanf("%d%d", &s, &v);
	if (s%v==0)
	{
		t = s / v + 10;
	}
	else
	{
		t = s / v + 11;
	}
	if (t<=480)
	{
		int t1=0;
		t1 = 480 - t;
		int t2 = t1 % 60;
		int t3 = t1 / 60;
		if (t2<=9)
		{
			printf("0%d:O%d", t3, t2);

		}
		else
		{
			printf("0%d:%d", t3, t2);
		}


	}
	else
	{
		int t1 = 1440 - (t - 480);
		int t2 = t1 % 60;
		int t3 = t1 / 60;
		if (t3<=9&&t2 <= 9)
		{
			printf("0%d:O%d", t3, t2);

		}
		else if(t3 <= 9 && t2 > 9)
		{
			printf("0%d:%d", t3, t2);
		}
		else
			printf("%d:%d", t3, t2);
	}

}