import java.io.*;
import java.util.*;
import java.awt.geom.*;

/**
 * Solution to Speed Can Cost You
 * 
 * @author vanb
 */
public class speed_vanb
{
    public Scanner sc;
    public PrintStream ps;
    
    /**
     * Driver.
     * @throws Exception
     */
    public void doit() throws Exception
    {
        sc = new Scanner( System.in ); //new File( "speed.judge" ) );
        ps = System.out; //new PrintStream( new FileOutputStream( "speed.solution" ) );
        
        for(;;)
        {
            int distance = sc.nextInt();
            if( distance==0 ) break;
            
            double s1 = sc.nextDouble();
            double s2 = sc.nextDouble();
            
            // Time, in seconds, to travel the given distance at the given speed.
            // distance/s1 and distance/s2 give the times in hours, since speed is in MPH
            // So, we've got to multiply by 60*60 to convert hours to seconds
            double t1 = distance * 60.0 * 60.0 / s1;
            double t2 = distance * 60.0 * 60.0 / s2;
            
            // Difference in seconds, rounded
            int dt = (int)Math.round( t1-t2 );
            
            // Break out hours, minutes, seconds
            int seconds = dt % 60;
            int minutes = (dt / 60) % 60;
            int hours = dt / 60 / 60;
            
            ps.printf( "%d:%02d:%02d", hours, minutes, seconds );
            ps.println();
        }
    }
    
    /**
     * @param args
     */
    public static void main( String[] args ) throws Exception
    {
        new speed_vanb().doit();
    }   
}