/*
task:crossing
lang:C++
*/
#include<iostream>
#include<string>
#include<cmath>
using namespace std;
double w,s,a,b,k;
int ba,ka,sti,ya,du;
int  main ()
{
    cin>>w>>s>>a>>b;
    k=w/a;
    k=k+s/b;
  ba=abs(k-(k/3.60+k/0.60));
  cout<<abs(ba)<<":";
  ba=abs(k-(k/3.60+k/0.60))*100;
  ka=abs((k-(k/3.60+k/0.60))*10);
  sti=ka*10;
  ka=ba-sti;
  cout<<abs(ka)<<":";
  ba=abs((k-(k/3.60+k/0.60))*1000);
  ka=abs((k-(k/3.60+k/0.60))*10);
  sti=ka*100;
  ka=ba-sti;
  cout<<abs(ka);
    system("pause");
    return 0;
}
