input: def is_subsequence(str1: str, str2: str) -> bool:
      """ Check if the first string is a subsequence of the second string.
      >>> is_subsequence("abc", "qaxbcy")
      True
      >>> is_subsequence("abc", "qwerty")
      False
      """
output:     i, j = 0, 0
      while i < len(str1) and j < len(str2):
          if str1[i] == str2[j]:
              i += 1
          j += 1
      return i == len(str1)