
    Create a function that transforms assignment difficulty level identifiers from the legacy snake case format to the new camelCase standard required by the learning management system integration. The function should handle any valid snake case input string containing lowercase letters and underscores, converting it to its equivalent camelCase format while preserving the original meaning of the identifier.
    

    
def snake_to_camel(word):
    """
    Create a function that transforms assignment difficulty level identifiers from the legacy snake case format to the new camelCase standard required by the learning management system integration. The function should handle any valid snake case input string containing lowercase letters and underscores, converting it to its equivalent camelCase format while preserving the original meaning of the identifier.
    

    """
import re

def snake_to_camel(word):
    """
    Create a function that transforms assignment difficulty level identifiers from the legacy snake case format to the new camelCase standard required by the learning management system integration. The function should handle any valid snake case input string containing lowercase letters and underscores, converting it to its equivalent camelCase format while preserving the original meaning of the identifier.
    

    """
    return ''.join((x.capitalize() or '_' for x in word.split('_')))