# keys values items

When working with dictionaries, it’s sometimes important to iterate over all the keys, or maybe all the values, or sometimes all the key-value pairs. Accessing all the keys is possible through the `keys()` method. Accessing all the values is possible through the `values()` method, while accessing the key-value pairs is possible through the `items()` method:
``````population = {
'US': 3295000000,
'Mexico': 129000000,
'Armenia': 3000000,
'Portugal': 10300000
}``````
``````for k in population.keys():
print(k.lower())

# Or even
for k in population:
print(k.lower())

# us
# mexico
# armenia
# portugal``````
``````for v in population.values():
print(v * 2)

# 6590000000
# 258000000
# 6000000
# 20600000``````
``````# population.items() is a list of tuples
# each tuple is a (key, value) pair: ('US', 3295000000)
for k, v in population.items():
print(f'{k.lower()}: {v * 2}')

# Alternatively
for k in population:
print(f'{k.lower()}: {population[k] * 2}')

# us: 6590000000
# mexico: 258000000
# armenia: 6000000
# portugal: 20600000``````

#### Challenge

Given a list of `n` patients with their blood pressure measurements, you are asked to calculate the average blood pressure for each patient. There are `m` measurements, each of the form `patient-name: blood-pressure`.
The first line of the input contains a single integer `m`. The next `m` lines contain the measurements of the form `patient-name: blood-pressure`.
The program should print the average blood pressure per patient in the order of appearance in the input. The format should be similar to the input `patient-name: average-blood-pressure`.
 Input Output 6 Anna: 100 Ani: 120 Anna: 120 Anna: 90 Ani: 100 Bob: 90 Anna: 103.33333333333333 Ani: 110 Bob: 90

#### Constraints

Time limit: 2 seconds

Memory limit: 512 MB

Output limit: 1 MB