#include<stdio.h>

int main(){
	
	int sort = 10;
	int s, v, t, T, h, m, H, min, hour;
	scanf("%d %d", &s, &v);
	 t = s % v;
	if( t !=0)
	{
		t++;
	}
	 T = t + sort;
	 H = T / 60 + 1;
	 m = T % 60;
	 min =  60 - m;
	 hour = 8 - H;
	if(hour >= 0)
	{
		printf("0%d:%d", hour, min);
	}
	else
	{
		int c = 24 + hour;
		printf("%d:%d", c, min);
	}
	
	return 0;
}