/*
TASK:crossing
LANG:C++
*/
#include<iostream>
#include<math.h>
using namespace std;
int main()
{
    double w,s,a,b,t,t0,t1,x;
    double h,m,sec;
    cin>>w>>s>>a>>b;
 
    int k=2;
    t0=w/a+s/b;
    t1=2*sqrt((w/2)*(w/2)+(s/2)*(s/2));
    if(t1<t0)
    {t=t1;}
    else
    {do
    {
        t1=2*sqrt((w/2)*(w/2)+((s/2)/k)*((s/2)/k))/a+(s/k)/b;
        k=k/2;
    }
    while(t0>=t1);
    t=t0;}
    h=t;
    do
    {h=h-1;}
    while(h>0);
    m=h*60;
    sec=m;
    x=sec;
    do x=x-1; while(x>0);
    sec=x*60;
    
    h=t-m/60-sec/3600;
    cout<<h<<":"<<m<<":"<<sec<<" \n";
    
//    cout<<t<<"\n";
    
   // system("PAUSE");
    return 0; 
}



















