"""Solution to 2020/07 Part 1"""

import pprint
from collections import defaultdict


# key: bag, value: list of bags in wich it can be contained
tree = defaultdict(list)


def words(sentence, start, end):
    """
    Strips consecutive words from a sentance

    Words are whitespace separated.
    Words are 1-indexed.
    """
    return ' '.join(sentence.split(' ')[start-1:end])


with open('input', 'r') as f:
    for line in f.readlines():
        source, targets = line.strip().split(' contain ')
        source = words(source, 1, 2)
        for target in targets.split(', '):
            target = words(target, 2, 3)
            tree[target].append(source)

# pprint.pprint(tree)

processed = set()
queue = set(['shiny gold'])
count = 0

while len(queue):
    cur = queue.pop()
    for target in tree[cur]:
        if target not in processed:
            queue.add(target)
        processed.add(target)

print(len(processed))