question: How many passes did Michael Irvin and Alvin Harper catch in all during the season?
#1 return Michael Irvin 
#2 return Alvin Harper 
#3 return catches of #1 
#4 return catches of #2 
#5 return #3 in  the  season 
#6 return #4 in  the  season 
#7 return number of  #5 
#8 return number of  #6 
#9 return sum of #7 and  #8