#include<cstdio>
using namespace std;
int main(){
	int s,v,h,m;
	cin>>s>>v;
	s/=v;
	m=s+10;
	if(m<480){
		h=(480-m)/60;
		m%=60;
		m=59-m;
		if(h<10,m<10){
			cout<<"0"<<h<<":"<<"0"<<m;}
		else if(h<10,m>10){
			cout<<"0"<<h<<":"<<m;}
		else if(h>10,m>10){
			cout<<h<<":"<<m;}
		else{
			cout<<"0"<<h<<":"<<"0"<<m;}
}
	else if(m>480){
	h=m+960;
	m=h%60;
	m=60-m;
	h/=60;
		if(h<10,m<10){
			cout<<"0"<<h<<":"<<"0"<<m;}
		else if(h<10,m>10){
			cout<<"0"<<h<<":"<<m;}
		else if(h>10,m>10){
			cout<<h<<":"<<m;}
		else{
			cout<<"0"<<h<<":"<<"0"<<m;}
}
	else{
		cout<<0<<":"<<0;}
	return 0;
}