#include <stdio.h>
int main()
{
    int T, t1;
    int s=0 ;
    int v=0 ;
    scanf("%d %d\n", &s, &v);
	T = s / v + 10;
	if (s % v > 0) {
		T++;
	}
	if (T <= 480) {
		t1 = 480 - T;
		int hour = t1 / 60;
		int min = t1 % 60;
		//printf("0");
		printf("0%d:", t1 / 60);
		if (min < 10) printf("0%d", min);
		else printf("%d", min);
	}
	else {
		t1 = 1920 - T;
		int hour = t1 / 60;
		int min = t1 % 60;
		if (hour < 10) {
			//printf("0");
			printf("0%d:", t1 / 60);
			if (min < 10) printf("0%d", min);
			else printf("%d", min);
		}
		else {
			printf("%d:\n", t1 / 60);
			if (min < 10) printf("0%d", min);
			else printf("%d", min);
		}
	}
	return 0;
}