How many years after being assigned to 1-25 did the 1-24 receive the Meritorious Unit Citation?
return being assigned to 1-25 ;return 1-24 receive the  Meritorious Unit Citation ;return when  was  #1 ;return when  was  #2 ;return difference of #4 and  #3 in  years
['select', 'select', 'project', 'project', 'arithmetic']