input: Write a python function to extract the first 100 characters from a given string.
  assert extract_first_100_chars("a" * 150) == "a" * 100
  assert extract_first_100_chars("Hello, World!") == "Hello, World!"
  assert extract_first_100_chars("Python programming is fun!" * 10) == ("Python programming is fun!" * 10)[:100]
output: def extract_first_100_chars(s):
      return s[:100]