#include<iostream>
#include<cstdio>

using namespace std;
	int s,v,p,h,c;
	
int main()
{
	cin>>s>>v;
	
	p=int(s/v);
	c=int(s/v)/60;
	
	if (s%v!=0)p++;
	p+=10;
	p-=c*60;
	h=7-c;
	if(h<=0)h=24+(8+h);
	
	if(h<10)printf("0");
	printf("%d:",h);
	if(60-p<10)printf("0");
	printf("%d",60-p);
	
	return 0;
}