Great! In Python, there are several widely used methods of iterating dictionaries. We'll review them here, in case you've forgotten them.

The tourist_arrivals dictionary contains numbers of tourist arrivals in Croatia in years 2012-2017.

tourist_arrivals = {
  2017: 17430580,
  2016: 15594157,
  2015: 14343323,
  2014: 13128416,
  2013: 12433727,
  2012: 11835160
}

Let's review the iterating techniques for dictionaries. Note that you should never add new elements or delete existing elements when iterating over a dictionary!

1. We can iterate over the keys:

sum = 0
for k in tourist_arrivals:
  if k > 2014:
    sum += tourist_arrivals[k]

2. There is an alternative version to the syntax you can use to iterate over dictionary keys. To emphasize that you're iterating over dictionary keys, you can use the keys() method:

   sum = 0
   for k in tourist_arrivals.keys():
     if k > 2014:
       sum += tourist_arrivals[k]
   

   Note that you can still modify the values under specific keys in a dictionary. Both methods we've presented so far will work in this case.
3. When we don't need the keys, we can simply iterate over the values:

sum = 0
for v in tourist_arrivals.values():
  sum += v
print('Total tourist arrivals in Croatia in years 2012-2017:', sum)

4. There are also situations in which we want to get convenient access to both keys and values.

max_year = 0
max_arrivals = 0
for k, v in tourist_arrivals.items():
  if v > max_arrivals:
    max_arrivals = v
    max_year = k
print('The best year in terms of tourist arrivals was', max_year, 'with', max_arrivals, 'arrivals.')