# This gives an inventory program for a grocery store

def main():
     Count = {} # keys are items; values are the quantities of those items
     done = False
     while not done:
         str = input( "Enter item and quantity; blank to exit: " )
         if str == "":
             done = True
         else:
             item, num = str.split( )
             quantity = eval(num)
             if item in Count.keys():
                 Count[item] = Count[item]+ quantity
             else:
                 Count[item] = quantity
     keys = list( Count.keys())
     keys.sort()
     for item in keys:
         print( "We have %d units of item %s"%(Count[item], item))

main()