How many numbers are there between ‘understand’ and ‘flower’ in step-IV? 

In first step vowel are arrange in increasing order of their appearance in alphabetical order from left to right and number is arrange in increasing order from right to left. In other step consonant are arrange in decreasing order of their appearance in alphabetical order from right to left and number is arrange in decreasing order from left to right.   Input:  53 broccoli 37 unjust 63 igloo 42 flower 18 plants 92 understand trumpet 87 Step-I : igloo 53 broccoli 37 unjust 63 42 flower plants 92 understand trumpet 87 18  Step-II : igloo 92 53 broccoli 37 unjust 63 42 flower plants understand 87 trumpet 18  Step-III: igloo 92 understand 53 broccoli unjust 63 42 flower plants 87 37 trumpet 18  Step-IV: igloo 92 understand 87 53 broccoli unjust 63 42 flower plants 37 trumpet 18  Step-V : igloo 92 understand 87 unjust 53 broccoli 63 flower 42 plants 37 trumpet 18  Step-VI : igloo 92 understand 87 unjust 63 53 broccoli flower 42 plants 37 trumpet 18  Step-VII: igloo 92 understand 87 unjust 63 broccoli 53 flower 42 plants 37 trumpet 18