input: Write a python function to compare two strings and count the number of mismatched characters.
  assert compare_strings("abcdefg", "accfghe") == 4
  assert compare_strings("hello", "hallo") == 1
  assert compare_strings("test", "tent") == 1
output: def compare_strings(str1, str2):
      min_len = min(len(str1), len(str2))
      mismatch_count = sum(1 for i in range(min_len) if str1[i] != str2[i])
      return mismatch_count + abs(len(str1) - len(str2))