Problem Statement 
 Victor has bought a new album from his favorite group. The album contains N songs that are each songDuration seconds long. There's 5 seconds of silence between each pair of consecutive songs.
At time 0, Victor starts listening to the album, and at that exact moment, his phone starts to ring. The phone rings every delay seconds, and each ring lasts 1 second (for example, for delay = 3, the phone will ring during the seconds 0, 3, 6 and so on). He cannot hear the rings while the music is playing because the volume is too loud. He can only hear rings during the silent intervals between songs. If a ring starts at the same moment that a song starts playing, he will not hear it. Similarly, if a ring stops at the same moment that a song stops playing, he will not hear it. The album will play exactly once, so after the last song ends, Victor will be able to hear the phone again. Return the time in seconds at which Victor will first hear the phone ring.


Definition 
 Class:  MissedCall  Method:  waitingTime  Parameters:  int, int, int  Returns:  int  Method signature:  int waitingTime(int N, int songDuration, int delay)  (be sure your method is public) 




Constraints 
  N will between 1 and 20, inclusive. 
  songDuration will between 1 and 180, inclusive. 
  delay will between 1 and 20, inclusive. 

Examples 
0)  
  Returns: 7  Second 0: The first song starts playing, and the telephone rings.
Second 14: The first song is playing.
Second 56: Silence.
Second 7: The telephone rings.
Victor only misses the first ring.



1)  
  Returns: 40  Victor will not hear the phone until after the album ends. 


2)  
  Returns: 40  Second 0: The first song starts playing, and the telephone rings.
Second 18: The first song is playing.
Second 913: Silence.
Second 1419: The second song is playing.
Second 20: The second song is playing, and the telephone rings.
Second 2122: The second song is playing.
Second 2327: Silence.
Second 2836: The third song is playing.
Second 3739: Silence.
Second 40: The telephone rings.
Victor misses the first two rings. 

