HackerRank Python - collections.Counter()

collections.Counter()
A counter is a container that stores elements as dictionary keys, and their counts are stored as dictionary values.

# Enter your code here. Read input from STDIN. Print output to STDOUT

from collections import Counter

num_shoes = int(input())
shoe_sizes = Counter(map(int, input().split()))
num_customers = int(input())

cost = 0
for _ in range(num_customers):
    size, price = map(int, input().split())
    if shoe_sizes[size]:
        cost += price
        shoe_sizes[size] -= 1

print(cost)