#include<stdio.h>
int main ()
{
	int s,v;
	int t,T1,T2,T3,T4;
	scanf("%d%d",&s,&v);

		if(s%v==0)
	{
		t=s/v+10;
		T1=t/60,T2=t-60*T1;
		T3=7-T1,T4=60-T2;
	}
	else if(s%v!=0)
	{
		t=s/v+11;
		T1=t/60,T2=t-60*T1;
		T3=7-T1,T4=60-T2;
	}
		if(T1>7)
		printf("%d:%d",19-T1,T4);
		else printf("0%d:%d",T3,T4);
	
	return 0;
}