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
      """
      i = 0
      j = 0
  
      while(i < len(str1) and j < len(str2)):
          if str1[i] == str2[j]:
              i += 1
          j += 1
  
      return i == len(str1)
  
output:     i = 0
      j = 0
  
      while(i < len(str1) and j < len(str2)):
          if str1[i] == str2[j]:
              i += 1
          j += 1
  
      return i == len(str1)