<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def to_identifier(s):
 """ Convert snake_case to camel_case. """

  if s.startswith('GPS'):
      s = 'Gps' + s[3:]
  return ''.join([i.capitalize() for i in s.split('_')]) if '_' in s else s