#include<bits/stdc++.h>
using namespace std;
int s,v,tt;
double t;
int nxtt;
#define NextTime 8*60
#define DayTime 24*60
int main()
{
	cin>>s>>v;
	t=(s+0.0)/(v+0.0)+10.0;
	tt=(int)(t)==t?(int)(t):(int)(t+1);
	if(tt>DayTime)tt%=DayTime;
	nxtt=NextTime-tt;
	cout<<(nxtt/60>=10?"":"0")<<nxtt/60<<":"<<nxtt%60;
	return 0;
}