#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
int can,beer,fs,ansh,ansm;
double hand,ach,wei,fsh,weis,ans;
cin>>hand>>beer>>ach>>wei;
//can
can=(int)hand;
fs=(hand-(double)can)*10;
can*=6;
can+=fs;
//cout<<can<<"\n";
//ach
ach=(double)beer*(double)can*ach/100;
//cout<<ach<<"\n";
//weis
weis=wei*8/100*0.05/100*1000;
//cout<<weis<<"\n";
//ans
ans=(ach-weis)/10;
ansh=(int)ans;
fsh=(ans-(double)ansh)*60+0.99;
ansm=(int)fsh;
cout<<ansh<<':'<<ansm;
return 0;
}